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M I R A C 3

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1. IRAFNAME 1981115 520 INSTRUME MIRAC3 Mid IR Array Camera INSTRUMENT 713 31 34 74 START TIME OF OBSERVATION UT 713 32 22 14 END TIME OF OBSERVATION UT OBJECT uy aurigae DATE OBS 15 11 98 DATE OF OBSERVATION UT DD MM YY TELESCOP IRTF RA 7 294999999829 01 RIGHT ASCENSION DEGREES DEC 3 078666666396e 01 DECLINATION DEGREES EQUINOX 1 950000000000e 03 EQUINOX FOR RA AND DEC LAMBDA 1 030000021274e 05 WAVELENGTH METERS FILTER1 3 000000000000e 00 POSITION OF FILTER WHEEL 1 FILTER2 1 000000000000e 00 POSITION OF FILTER WHEEL 2 FILTER3 1 000000000000e 00 POSITION OF FILTER WHEEL 3 OBSERVAT Mauna Kea LOCATION OF OBSERVATION SOFTVER 7 150000095367e 00 VERSION NUMBER FOR MIRAC SOFTWARE CHOPFREQ 2 89723849296 00 CHOP FREQUENCY HZ FRAMETIM 1 966079883277e 02 FRAME TIME SEC ITIME x 8 493465423584e 00 INTEGRATION TIME SEC IN EACH BEAM NODWAITT 3 000000000000e 00 BEAM
2. FRPERCOI 8 FRAMES PER COIMAGE CHOPWTFR 0 CHOPPER WAIT FRAMES CHOPWAIT 1 529173278809e 01 CHOP WAIT TIME MSEC NUMCHOPS 0 NUMBER OF CHOP CYCLES SKYFLUX 2 351335205078e 03 SKY FLUX AVG CNTS OFF SRC SKYRMS 1 729015469551 00 RMS OF LAST 5 SKY FLUXES SKYDIF 3 094238281250e 00 DIFFERENCE FROM LAST SKY FLUX 1 745402693748e 00 AMBIENT TEMP C 2 1 446844005585e 01 TEMP INSIDE CAMERA ELEC C ERTEMP3 2 673849105835e 01 TEMP OF A D COMPONENT C AIRMASS 1 128493309021 00 AIRMASS OF OBSERVATION RAOFFSET 0 000000000000e 00 RA OFFSET ARCSEC DEOFFSET 0 000000000000 00 DEC OFFSET ARCSEC FILEDIR e Nd981115 BAKUPDIR 4 d981115 15 5 9132 FILTER 1 STEP POS FW2STPOS 0 FILTER 2 STEP POS FW3STPOS 0 FILTER W3 STEP POS PUPILPOS 2 PUPIL POSITION 2 35 COMMENT THE ORIENTST SHOWS THE ORIGINAL ORIENTATION OF THE DATA ORIENTST ULNYY DBLREAD 0 DOUBLE READ FLAG O FALSE WAITCYCL 14 CHOPPER WAIT CYCLES BURSTCYC 17 BURST DELAY CYCLES SUBROWST 0 SUBARRAY ROW STAR SUBROWND 3 SUBARRAY ROW END SUBCOLST 0
3. 1 p Color of Arcsec Grid FWHM Display Mode FWHM displ A Black Small display limit 0 B Blue Large display limit 5 C Green Number for running AVG 5 Display On Off On Red Magenta Brown Display Mode LtGray DkGray FWHM Display J LtBlue Sum of Source K LtGreen Peak Value LtCyan Display Sky Flux M LtRed N LtMagenta O Yellow Arcsec Grid White Arcsec Grid lines On Grid Spacing arcsec 5 Color of Arcsec Grid Black 12 2 2 DISP Load MOS Display Current Data Format MIRAC Auto Gain Mask FField gt Load display buffer F Mod 3 Accumulate Mosaic Spectra Format Current Noise MIRAC Processed FITS Operation ASCII Replay J L F Mask Array p Auto Gain Mask FField Edit Mask Save Mask image o bad1106 msk Mask Auto o hilll4 msk Read Mask image o bad1106 msk Gain Auto OFF Output bad pixel list FField Auto OFF Import pad RISE i Disregard low points using map Dynamic Masking QET Cutoff high points using map Edit Mask Array mio Mask Reset Clear masked pixels 154 MIRAC User s Manual F S Set C Clear M Move E Exit Mosaic functions 5 p Select
4. 61 Figure 9 2 Pull down Menu for Next Observing 65 Figure 9 3 Sky Modulation in the Chop Data Taking Mode 69 Figure 9 4 Sky Modulation in the Chop Nod Data Taking Mode 69 Figure 9 5 Sky Modulation with source in all four Chop Nod Beams 70 Figure 11 1 Grayscale Display Mode 84 Figure 11 2 Contour Display Mode 85 Figure 11 3 The Slice Display Mode 86 Figure 11 4 Histogram Display i eR RENE EXE MSN M DAR 87 Figure 11 5 Radial Plot of Simulated Star with Gaussian Fit to Profile 88 Figure 12 1 Scope Utility Display sss Seer a A REIR EAR ARA EA SA 93 Figure A3 1 Plot of MIRAC3 N band filter and atmospheric transmission 115 Figure A3 2 Plot of MIRAC3 Q band filter and atmospheric transmission 116 Figure A3 3 CVF Calibration July 9 1994 and May 24 1995 118 Figure 14 1 Cryostat Vacuum 180 Figure AT4 2 Cryostat Cooldown 2 cede eges he oe ee 181 Figure 14 3 MIRAC Control Room Layout 184 Figure Al4 4 MIRAC PC Connector Positions 185 Fi
5. 145 A12 1 OBS Command Line Menus 145 5 23 99 Contents AI2 2 DISP Command Line Menus 152 12 3 UTIL Command Line 158 12 4 PRN Command Line Menus 162 Appendix 13 Shipping Procedures and Shipping Inventory 163 A131 Shipping Procedures y s Sm qoc ks Ra ats SIA RR RUN 163 A13 2 Shipping Crate List 164 A13 3 Shipping Labels for and UKIRT 165 A13 4 Shipping Inventory and Packing 166 Appendix 14 Hardware Preparation and 179 14 1 Observatory Preparation Requirements 179 ATT2 Unpaeking e bi tcv ev 179 Cryostat Preparations pcr RYE S ER RR REY p 179 A14 3 1 Protection of Detector and 179 14 3 2 Cryostat Vacuum 179 A14 3 3 Liquid Nitrogen Cool 180 14 3 4 Liquid Helium Cool 181 14 3 5 Topping Off Liquid Helium Reservoir 182 14 3 6 Cryogen Transfer at the Telescope
6. 182 A14 3 7 Measuring Cryogen 182 14 3 8 Cryogen Capacity Hold Time and Consumption 182 A14 4 Control Room Setup 5 qed teeter EA 183 14 5 Camera Installation at Telescope 185 A14 6 Cabling and Connections 187 14 7 Temperature Monitor and Controller 192 14 8 Setting the LN Shield shutter Pupil Stop and Magnification 194 14 9 TV Relay Optics Pupil Setting 195 Telescope Balance eee See 196 14 11 Dichroic Alignment 196 A14 11 1 Dichroic Alignment using Pupil Imaging Lens 196 14 11 2 Dichroic Alignment using Sky Dome Contrast 197 14 12 Setting the Telescope Chopper Parameters 198 14 13 Checking the Telescope Collimation 199 14 14 Setting the Telescope Nod Parameters 200 Appendix 15 MIRAC Cryogen Instructions 203 Appendix 16 Checking and Trouble Shooting 205 A16 1 Software or Digital Logic Lockup in PC DSP or Camera 205 16 2 Power Supply
7. 9 Zid Telescopeand Sky Emissivity gutture 11 3 Observing Run Arrangements 13 3 1 Observing Proposals 58 13 3 2 Observatory 14 3 2 1 Kitt Peak Arrangements 14 3 2 2 Mt Hopkins Arrangements 14 3 2 3 Hawaii Mauna Kea Arrangements 14 Requirements List eos Sees OVE he eed See eee EV 15 3 4 Cryogenics COS S 19 17 4 Software Preparation ed pn RACK Daa DEMARIS Shae acea erre de oss 19 4 1 Object Lists and Air Mass Charts 19 4 2 Offset and Command Files 19 4 3 Establishing an Individual Guest Account 20 5 Start and End of Run Setup and Shutdown Check Lists 21 5 1 Preparation of MIRAC after Shipping or Storage 21 5 2 Start of Run Setup Tasks a 53 toos fu eset tor sut see i pa a v bl ct ao 21 5 3 End of Run Shutdown Tasks i cede ade ee Dba pede epee ee P Au ers 26 5 3 1 Initial Control Room End of Run Tasks 26 5 3 2 Telescope Chamber End of Run Tasks
8. 104 A1 3 Obtaining a Gain co esu cules ees 105 1 4 Calibration of IR 105 Appendix 2 Standard Mid IR Stars 107 A2 1 Standard Star Tables 107 A2 2 Notes on Standard Stars herded du 111 Appendix 3 MIRAG Filters cue d Eris RETI AP dog eh es 115 PIOS en ME E 115 29 2 CVF CAlDEaDOD Sete Xu Sco tbe hl aoe 116 Appendix 4 The OBSLIST Program 119 Appendix 5 The AIRMASS 123 Appendix Mantal Eog 511 ls E Lowest era E Lees 125 Appendix 7 The mrc2fts Program 131 Appendix 8 Atmospheric Extinction and the aircor Program 133 A8 1 Infrared Atmospheric Extinction 133 48 2 The aircor Program 2 252499 ERREUR EEG 134 Appendix 9 MIRAC Image and Header File 135 Appendix 10 Reduction of MIRAC Data using 137 Appendix 11 Files Necessary for MIRAC Program 143 Appendix 12 Command Line Menus
9. 218 Table A17 6 Array Resistance Temperature Sensor Calibration 218 Table ANT 7 Clock IMputs 2 doo sut san Lacu beat dpa 2 9 Table A17 8 Filter Wheel S witches 4 uns ox Sas eon Pee d has oes 219 Table A17 9 Temperature Control 220 Table A1710 Preamp ERE XS REESE Mor Sr tae 220 Table A17 11 Digital and Signal Ground Shorting Connectors 220 Table A18 1 Power Supply Voltage and 221 Table A18 2 Power Supply Ratings 222 Table A18 3 Power Supply Power Dissipation 222 5 23 99 1 Organization of MIRAC Manual 1 1 Organization of MIRAC User s Manual The MIRAC User s Manual provides information and check lists for shipping setup preparation observation data reduction and maintenance The filled circle indicates chapters most useful to review before an observing run This manual and other information about MIRAC can be obtained from the MIRAC home page on the World Wide Web Section 2 1 Subject Chapters Appendices Organization of the manual and performance of MIRAC 1 2 Preparation for an observing run e 3 4 Al A4 Setting up and shutting down for a run and for a night of observing 5 6 Observing with the ca
10. 228 Appendix 21 Tape 235 A21 1 Backing up Data with NovaTar on MIRAC PC DAT Drive 235 21 2 Backing up Data with NovaBack on MIRAC PC DAT Drive 235 A21 3 Backing up Data on a Unix 236 A21 3 1 Basic Unix Tar 8 236 A21 3 2 Steward Observatory Tar 237 Appendix 22 Weather and Tau Information from the Web 239 A22 1 Arizona Weather Information 239 A222 Mt Graham Tau Meter Data 239 A22 3 Mauna Kea Weather Information from University of Hawaii 239 A22 4 Mauna Kea Weather Information from the Gemini Home Page 239 A22 5 UKIRT Weather Information for Mauna 239 A22 6 CSO Tau Meter Data for Mauna Kea 239 Appendix 23 Observatory Addresses and Telephone Numbers 241 Appendix 24 MIRAC Addresses and Telephone Numbers 243 5 23 99 Contents vii List of Figures Figure 2 1 Relative spectral quantum efficiency of the Boeing Si As BIB detector 4 Figure 2 2 Drawing of MIR AC3 cryostat oi cen vic b eve ge REIR ORE ER r 5 Figure 9 1 The MIRAC Main Screen OBS Command
11. UNDA 89 quit 31 35 56 80 100 145 152 158 162 229 R A 19 74 96 120 136 196 200 2 ceret 89 157 replay 61 64 72 75 80 154 row 50 82 83 85 86 102 136 147 148 151 159 207 209 RS 232 67 72 73 191 192 200 SIN Ne Sh 104 105 133 scope 12 93 94 144 158 161 194 197 199 setup 1 14 16 19 21 22 28 30 31 33 36 49 84 88 89 93 116 117 125 127 154 157 161 170 179 183 188 223 228 shell 32 42 44 96 119 123 150 158 231 shift 81 91 95 104 118 207 210 220 shipping 1 13 15 17 21 30 163 166 177 shorthand notation 60 65 80 81 simulate data 59 94 sky emission 103 SHEE a 79 85 86 88 155 smooth ee 97 159 226 source 6 9 11 19 32 34 39 40 42 43 47 49 50 54 55 61 63 66 68 71 74 76 78 82 87 95 97 99 101 107 113 114 116 120 122 123 125 133 136 143 145 147 152 154 159 173 181 198 200 207 208 210 228 230 239 source list 34 119 120 123 standard star 9 40 42 43 46 50 55 56 105 107 111 114 119 123 133 201 step 47 49 74 75 82 90 99 116 118 136 195 196 198 200 201 206 Steward Observatory 1 3 4 10 11 13 14 17 21 22 31 49 119 121 123 164 165 200 237 239 241 243 subtract 70
12. Value displayed 10 000 IB Min Value displayed 0 000 Auto gray max level On Auto gray min level On Printer Setup 4 5 1 Printer Select Printer PostScript Previous page Resolution Max resolution A PostScript gt Orientation of plot Landscape PostScript CMYK gt Horizontal size 8 000 BostScript Color gt Vertical size 7 000 D Raw Image gt Destination Disk File E oshiba P321 gt Filename for Output MRCGRAPH F Toshiba P321SL gt Toshiba P341 gt Toshiba P341SL gt I Toshiba P351 gt p Resolution J Toshiba P3515L gt Next page A 60 x 72 dpi B 72 x 72 dpi C 120 x 72 dpi D 240 x 72 dpi 5 22 99 12 2 DISP Command Line Menus 157 Orientation of plot F Portrait Landscape p IL Nowhere LPT1 LPT2 LPT3 COM1 COM2 COM3 COM4 Disk File For Other Plot Modes Setup Same as DISP Begin Contour Parameters Plot Params Edit Redraw Values Level Hardco Graph print Output ASCII file Fit Exit 158 MIRAC User s Manual A12 3 UTIL Command Line Menus UTIL Functi Arith Macro Temp Scope Camera OBS DISP PRN Quit A12 3 1 UTIL Functi F Function System Info Output ASCII files FITS file output Gain Map c
13. Turn on camera electronics switch Additional green LED lights should come on immediately In 1 3 seconds a relay should click the red LED light should come on the green LEDs SHOULD NOT DIM and the fans in the power supply should come on The DetTemp on the Monitor status display should rise and stabilize at 5 3 K If any of the green lights dim turn off the electronics power and begin trouble shooting The orange LED lights Command Link on the PC panel and Data Link on the camera connector panel should come on indicating that the fiber optic communications are operating ol 34 13 14 15 16 17 MIRAC User s Manual The temperature monitor switch must be on for the camera electronics switch to cause the camera power to turn on Ifthe AC power to the camera is interrupted and restored the camera power will not come on until the camera electronics switch is recycled off and on Initialize Camera Obs Init IO init yes Obs Init Camera init yes NOTE If the filter controller is not connected or powered this will result a long timeout when the program tries to command the filter motor to a quiescent state Instead use UTIL Camera Init The I O init command initializes flags in the PC DSP interface The Camera Init command sends a master reset and all the camera parameters to the camera electronics If the camera parameters are later changed using the OBS HEADER menu the changed parameters are aut
14. te ooi oe 205 A16 3 Fiber Optic Command and Data 205 Biases and Clocks oh wd o ror term S er teer a Ra e RU 205 16 5 Running the Camera without the 206 16 6 Running with the Array at Room Temperature 207 MIRAC User s Manual Alo 7 Array Operation lt lt REIR R RE LAE EA RR LU 207 Appendix 17 Cryostat Inputs and Outputs 213 Appendix 18 Power Supply Voltage Current and Power 221 Appendix 19 Cryostat Disassembly and Assembly 223 19 1 Basic cryostat disassembly 223 A19 2 Removing the optics and filter wheel assembly 224 A19 3 Removal of detector stage assembly 225 19 4 Removal filter wheels and filters 225 A19 5 Removing the upper section of LN2 radiation shield 225 A19 6 Removing the upper section of LHe radiation shield 225 19 7 Reassembling Cryostat 52 52 3G mE UOS exce ea ae be pe des 226 Appendix 20 VMS DOS UNIX Command Reference 227 A20 1 Command Cross Reference Guide 227 A20 2 SunOS Quick Reference
15. 1 8 1 4 8 4 1 3 1 9 3 45 3 2 4 8 4 3 1 7 1 8 0 82 0 2 4 8 2 12 3 08 1 34 1 23 1 35 3 16 2 51 801 Tenue A 5195 D VITIA Alpha Aql Alpha Ari Alpha Aur Alpha Boo Alpha Car Alpha CMa Alpha CMi Alpha Her Alpha Hya Alpha Lyr Alpha Ori Alpha Sco Alpha Tau Beta And Beta Gem Beta Peg Epsilon Mus Eta Sgr Gamma Gamma Cru Gamma Dra IRC 10216 Lambda Vel Mu Cep Mu UMa Sigma Lib MIRAC MIRAC MIRAC MIRAC Cohen Hanner MIRAC MIRAC Cohen MIRAC MIRAC MIRAC Cohen MIRAC Cohen MIRAC MIRAC MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC MIRAC MIRAC Hanner MIRAC MIRAC MIRAC MIRAC MIRAC MIRAC MIRAC RA 19 48 02 04 05 12 14 13 06 22 06 42 07 36 17 12 09 25 18 35 05 52 16 26 04 33 01 06 07 42 23 01 12 15 18 14 19 43 12 28 17 55 09 45 09 06 21 42 10 19 15 01 8 44 23 13 45 56 19 26 52 40 16 38 05 21 14 26 08 26 38 44 07 23 26 19 16 24 35 21 28 08 27 48 67 41 36 46 10 29 56 50 5 1 30 13 31 43 14 58 33 41 45 25 05 2 2 0 22 0 64 1 78 3 3 04 1 31 1 35 1 37 0 65 3 48 1 21 1 22 4 3 7 2 8 2 9 1 83 1 89 1 09 1 12 2 22 2 29 1 42 1 55 0 52 3 16 1 3 0 6 1 56 1 65 0 86 1 41 Table 2 2 Standa
16. 2 One and two airmass With the dome and mirror covers open and tracking off obtain 10 grab mode images at a 2 sec integration time with the telescope at the zenith and at 2 airmass elevation 30 degrees 3 Off source frames Use off source frames from a normal set of observations chop chop nod or nod which cover a reasonably large change in sky flux Use one set for high and another for the low flux observations In each case save the gain map in the observing directory using the Save command from the OBS DISP menus Use file name that identifies the filter and date i e O 1171008 GAN The header will be the same as one of the GRAB observations used to make the map and the Comment field will contain a record of the images used to make the map 10 3 Preparing a Flat Field The flat field image is subtracted from the data image to remove any gradients in the background In normal observing mode when the telescope is chopping and nodding the telescope beamswitching takes care of background gradients so a flat field is not necessary The flat field is useful however when grabbing images The flat field is subtracted from the on source grab producing an image of the source without background This mode is useful when trying to acquire an object or focusing since the image rate can be much faster than if the telescope is chopped and nodded The best way to obtain a flat field image is to move the telescope beam off the sou
17. Figure A16 7 shows the signal processor timing Each signal processor board servers two channels with separate amplifiers and A D s and shared digital coadder and coadder memory Each FSTCLK transition advances the array multiplexer one block to a new set of pixels At the last memory write of a coadd sequence the data is directed to a FIFO memory and the coadder memory locations are zeroed The A D convert and coadder memory write are triggered at the trailing edge of the timing pulse The analog signal in the figure represents the transition from one pixel to the next with a time constant of the array output source follower and cable capacitance plus any additional selectable filtering on the board The track and hold hold and A D convert begin toward the end of the pixel sample time The two A D outputs are then sequentially selected and coadded into the coadder memory The shading shows the timing path for processing one pixel Figure 16 8 shows the timing of the array read in burst mode with chopping The chopper external reference signal is derived from the camera timing as shown The array is read continuously during 5 22 99 the chop cycle this example the read time is 1 092 msec and the chop frequency 10 Hz Each box in all but the last line of the figure represents single read of the full array At the first read coadd the array is reset the coadder output for each channel written to a separate FIFO memory For t
18. 26 19 14 26 5 1 30 36 46 38 44 10 29 8 44 58 33 27 48 2 2 1 83 1 89 0 64 2 8 2 9 1 78 1 31 1 35 1 37 0 65 1 09 1 12 1 56 1 21 1 22 0 6 0 86 1 42 3 16 3 3 04 1 41 3 7 3 48 1 3 1 55 0 52 0 22 1 65 2 29 2 22 3 8 2 05 2 02 0 71 3 3 05 1 86 4 5 1 43 1 4 1 36 0 68 1 2 1 22 1 75 1 3 1 36 3 5 0 95 1 6 3 33 3 12 3 15 1 46 4 2 3 73 1 4 1 7 0 76 0 2 2 3 2 47 2 45 4 8 1 8 1 78 0 6 2 8 2 77 1 92 4 16 1 44 1 36 1 36 0 68 1 12 1 09 1 41 1 16 1 12 4 4 0 7 1 3 3 05 2 96 2 93 1 4 3 9 3 4 1 2 1 4 0 62 0 2 2 1 2 2 2 2 Wavelength um Magnitudes 7 9 2 0 78 2 95 1 9 4 75 1 45 1 37 0 68 1 22 1 65 1 24 72 0 87 1 5 3 14 3 08 1 6 4 4 3 8 1 3 1 57 0 7 2 7 2 45 8 8 2 1 96 1 98 0 78 2 98 2 95 2 97 1 9 4 75 1 45 1 38 1 35 0 68 1 22 1 21 1 23 1 65 1 24 1 25 7 2 0 93 1 5 3 36 3 16 3 12 3 14 1 6 4 4 3 85 1 3 1 61 0 7 0 73 3 3 2 37 2 45 2 44 9 8 2 05 2 07 0 75 3 3 06 1 9 5 1 1 5 1 39 0 7 1 19 1 24 1 73 1 31 7 6 0 95 1 73 3 37 3 13 3 18 1 6 4 5 3 88 1 44 1 7 0 78 0 8 4 2 2 51 2 5 10 3 2 07 2 1 0 75 3
19. 40 61 72 75 77 79 80 93 99 101 144 flip25 48 82 83 96 98 127 152 159 201 focus 16 17 26 40 47 49 56 127 129 167 184 188 195 196 198 200 frequency mode 86 REA 57 100 131 227 function 42 66 gain 40 50 60 61 68 76 78 95 99 101 103 105 131 140 141 159 gain matrix 61 gaussian 25 48 62 85 88 89 152 GRAB 40 50 60 63 66 68 70 72 75 76 91 117 132 135 140 146 150 194 197 grayscale 21 50 61 62 82 84 88 98 hardcopy 87 89 91 hardware21 42 57 59 62 66 71 132 148 174 179 206 header 19 21 23 24 31 34 39 40 42 44 48 59 62 65 68 71 73 74 76 80 82 93 96 101 117 125 133 135 138 140 144 146 152 154 155 161 194 197 200 201 206 208 228 header 44 59 101 135 helium 3 13 16 17 181 183 help oua Seb ees 67 94 137 143 227 histogram 522222222222 75 85 87 hold time 126 182 183 ignore 94 increment 74 116 147 integration 9 35 39 40 44 45 48 56 61 65 70 71 74 76 77 95 101 105 117 135 200 201 207 208 210 211 interpolation 85 5 22 99 IRoattdy voveo tee aa ERR 135 201 IRAF 95 96 99 100 137 139 141 3 4 6 9 11 13 15
20. 9600 8 bits Fh Fh Of 146 MIRAC User s Manual A12 1 2 OBS Mode Observe or 777771 Chop or Grab Chop Chop Nod Two beams Step Off How many Obs per Run 2 Fast Data mode Off Continuous coimaging Off Ask for offsets Off Read Offsets every Run Off r Nod 1 Offset file name o tinid off Beep Deutsch Mode loft Do all offsets in 1 Run On Two beams Use Command file for run Off Beams The Command file name Off Mode FlipFlopChop Off A12 1 3 OBS Header p Header Information Parameters Observing Parameters gt Int Time per beam sec 5 068 Source Information gt Frame Time ms 17 4763 Filter Settings gt Read Time ms 1 0923 Hardware Settings gt 1 1 1 1 psec Telescope amp Site gt Chop Frequency 8 803 Data Files gt Total Frames 1 beam 291 i Burst Mode On Sample Mode Single How Many Frames Coimage 3 Nod and Chop parameters gt Sample Mode Level of Flux Medium Max Frames Coimage 4096 Single Chop wait reads 2 Double Burst wait cycles 7 L Time ms 2 Pixel Time 3 A 1 0923 1 1 psec B 2 1845 B 2 1 usec Cs 4 3691 Ca 4 3 psec
21. Infrared secondary if it in not at telescope MIRAC TRAVELING KIT Taken with personal baggage 05 22 99 Shipping folder with instructions and shipping labels Shipping inventory Plastic case with Jackknife or scissors Sharpie Pens MIRAC Users Manual Master Copy Current Observing proposals Current Logistics Airmass lists Object lists 178 MIRAC User s Manual 5 22 99 14 Hardware Preparation and Setup 179 Appendix 14 Hardware Preparation and Setup A14 1 Observatory Preparation Requirements The observatory preparation requirements are given in Section 3 3 A14 2 Unpacking Unpacking should be carried out according to the instructions in Section A13 4 A14 3 Cryostat Preparation A14 3 1 Protection of Detector and Cryostat At all times when the cryostat is not connected to the camera electronics the connector caps with conducting foam should be on the cryostat signal and clock connectors When these caps or cables are installed or removed care must be taken to keep hands in contact with the cryostat case to prevent static electricity discharge to the connectors The cryostat window cover should be on the cryostat at all times when not observing The LN shutter magnification and pupil actuators should be withdrawn from the cryostat when transporting it 14 3 2 Cryostat Vacuum Pumpdown For vacuum pumping open the LN2 shutter and set the pupil slide to the largest f 15 CCW extreme position pupil opening
22. The pupil imaging lens can also be used with a star in the center of the field to observe the uniformity of the illumination of the telescope aperture by the star A14 11 2 Dichroic Alignment using Sky Dome Contrast The pupil and magnification should be properly set as described in Section A14 8 The alignment procedure depends on the contrast between the cold sky and the warm mirror cover or dome shutters at mid infrared wavelengths If the camera beam is correctly aimed at the secondary the camera will view the sky via the secondary and full primary aperture If the beam is totally off the secondary the camera will view the sky directly Set the wavelength to 11 7 and the frame time to maintain linear operation for dome temperature flux Use the MIRAC menu UTIL Scope with the following settings First display column Second display column 128 Offset for second display 0 Make Scope Header 2 Obs Header UTIL Scope Edit Scope Header Observing Parameters Int Time 2 UTIL Scope Change Display Parameters Display size limits Max x 128 Min x 0 Max y 2000 Min y 2000 198 MIRAC User s Manual Auto x off Auto y off Change Max Min y as required for adequate sensitivity The steps are Step 1 Set the telescope to the zenith or some other direction to avoid daytime sun It is most convenient if the slit is oriented N S or E W Open the telescope shutter wind screens and mirror cover Watch the scope display as a wind scree
23. bias shield Case system ground Clock reference Signal Return Connected Signal Return to coax Dewar Case shield inside CO 7 7 1 2 3 4 2 6 5 22 99 18 Power Supply Voltage Current and Power Appendix 18 Power Supply Voltage Current and Power Table A18 1 Power Supply Voltage and Current Switch Power Pos Supply Preamp Preamp Bias Bias Clock A D Signal Proc Signal Proc Digital Temp Monitor Temp Monitor Shunt resistance 10 4 milliQ Circuit V 15 15 15 15 4 9 5 2 15 15 5 15 15 Backpln V 19 9 19 19 1 12 0 8 6 19 5 19 2 7 5 19 19 1 Supply V 20 8 20 5 20 3 21 3 12 0 10 7 21 2 20 9 11 9 20 2 20 2 Test V 19 0 19 2 19 1 19 2 11 9 9 8 20 4 20 3 10 3 19 1 19 2 Shunt mV 1 9 1 5 4 1 0 9 8 19 4 17 4 97 8 5 221 Current Amp 18 14 058 038 096 94 1 9 1 7 9 4 077 048 222 Switch Pos Power Supply Preamp Preamp Bias Bias Clock A D Signal Proc Signal Proc Digital Temp Monitor Temp Monitor Table A18 3 Power Supply Power Dissipation Switch Power MIRAC User s Manual Power One Model HAA24 0 6 HAA24 0 6 HB12 1 7 HB12 1 7 HN24 3 6 HN24 3 6 HE12 10 2 HAA24 0 6 Regu
24. gt Die cl gt imarith mask117 mask117 mask117 cl wfits mask117 mask117 fts File 1 mask117 gt mask117 fts 1 5 AIRMASS Size 32 x 20 pixtype short bitpix 16 blkfac fixed scaling none 2 Header 1 Data logical 2880 byte records written cl wfits gainll7 gainll7 fts File 1 117 gainll7 fts 1 5 AIRMASS Size 32 x 20 pixtype real bitpix 32 blkfac fixed scaling none 2 Header 1 Data logical 2880 byte records written cl mrc2fts c921210a r 200 216 e 4 g gainll7 fts m mask117 fts Reading mask file mask117 fts Reading gain file gainll7 fts Reading c921210a 200 writing 921210a 200 Reading c92 1210a 201 writing 921210a 201 o O N 1 12 513 20 21 122 23 24 R R R R cl E N 2 R 2 2 f c c i i NTFNANOQOQA 5 22 99 A10 Reduction of MIRAC Data using IRAF eading c921210a 216 writing 921210a 216 1 gt aircor 921210 0 2 r 200 218 eading 921210a 200 writing 921210a 200 eading 921210a 201 writing 921210a 201 eading 921210a 216 writing 921210a 216 l gt rfits 92 2 oldirafnamet RAF filename a ile 0001 ALPHA TAU Size 130 x 84 File a0001 restored to IRAF File 1921210 200 ile 0002 ALPHA TAU Size 130 x 84 File 0002 restored to IRAF File 1921210 201 1 gt 15 192
25. 0 30667 Avg 0 0025 Num 16384 Background RMS 0 30096 Avg 0 0009 Num 16107 Source Sum 26 5 Num 277 lt 39 5 Flux 3488 5 RMS 0 01 DIF 0 0 Limits A D lt 5415 1320 gt LinMax 4190 FullW 7508 FrameErrors Flux MaxMin 3585 339225 BLIP 1 04 Lev Medium OutOfRange lt OBS 4 02 97 14 12 03 c970402a 010 Simulated Star IDLE 0 00 0 02 O 16 DISP 4 02 97 14 11 49 21 Data not saved Simulated Star Mode Current Figure 9 2 Pull down Menu for Next Observing Parameters Most parameters that are set in the submenus are not changed until exiting the menu This allows the user the option to cancel changes made Some things cannot be canceled such as overwriting files and moving filters but most parameters can Some functions in submenus such as the image display buffer loading automatically return to the top line menu after executing Other functions such as altering header parameters changing display options etc must be exited manually Pressing the PageUp key moves up one submenu level so if the current submenu level is 2 pressing PageUp twice will return to the top line menu The ESC key will immediately return to the top line menu from any submenu level Both of these methods save any changes made in the submenus made since leaving the top line menu The Alt F1 key will also exit to the top line menu but it ignores all cancel able changes made since entering the submenu from the top line In the following description
26. 26 5 4 Complete Shut Down and Packing 30 6 Nightly Startup and Shutdown Check 45 8 31 6 1 Nightly 31 6 2 Nightly Shutdown Tasks 35 7 Observing Procedures and Check Lists 39 ii MIRAC User s Manual 7 1 Check List for each Setof 39 7 2 Check List for Nights Observations 40 7 3 Wavelengths Frame Times Frame Filter Link Files and Filter Change Times 40 TA Macto AldS i25 citac eeru AP LO a E Us 42 Command Filesi set ea Res aE E ind vu tette oa E 43 7 6 Offset Piles slice ad esos State oed oo e ELS E a 46 TT HOCUS Sel Sood sas Cobb eade atl 47 7 8 Acquisition of Star and Focus 48 7 9 Final Telescope Focusing 49 1 10 Autosuiding 5 2 49 TIN Autoguiding at UKIRT 256 SEEN eae 49 TAZ Observing TIMES 4 EQ RE 49 1 13 Calculatng Image Seale Sees ue tee eae 50 T I4 Printing Images her wea oe eel 50 8 Short Form Instructions for Running MIRAC
27. 40 44 46 48 55 56 60 66 74 82 101 104 120 122 135 136 151 153 194 195 198 200 201 arithmetic 4 69 70 97 159 229 array 3 4 7 9 11 25 40 46 47 61 63 71 74 75 77 85 87 94 98 101 105 135 136 152 153 183 193 198 201 206 211 213 215 217 219 arrow keys ves ves v 21 31 64 75 ASCII output 95 158 auto functions 93 autoscaling 84 background 3 7 11 41 62 63 66 68 70 76 78 80 85 89 101 103 104 117 195 230 232 backing 36 235 237 balance ot es Bh 196 bias8 73 125 135 148 151 168 175 176 192 205 207 208 210 213 216 218 220 222 epu wed 7 8 60 63 125 152 BOR ens 22 31 100 236 BOROBS 21 22 100 CMMIRAC 23 59 119 123 145 162 245 Index cables26 28 30 37 164 169 171 175 176 179 187 188 191 192 196 224 225 calibration19 49 50 94 105 107 116 118 125 143 193 218 cancel icu 65 67 151 162 catalog 19 23 32 34 39 40 54 107 114 119 123 127 143 144 177 centroid 62 81 87 154 chop 6 9 11 21 23 24 31 33 35 39 40 42 43 47 50 55 56 60 63 66 68 72 75 76 79 95 97 99 101 104 117 125 127 129 131 132 135 136 145 147 150 191 198 200 211 214 chopper 4 9 11 15 16 29 34 35 49 68 71 72 101
28. 77 81 97 105 140 tape 1 26 28 31 36 57 99 164 169 170 172 174 199 224 225 227 233 235 238 telescope 3 4 6 9 16 19 21 22 24 26 31 33 37 44 46 50 55 59 62 68 70 72 74 76 78 83 99 101 105 119 123 125 127 149 151 167 172 177 182 186 188 191 194 201 203 236 237 239 241 242 telescope control 14 15 19 24 31 33 34 68 72 73 119 123 151 183 191 199 201 telnet ice pw Mak aren RIS 227 temperature 8 11 27 31 33 35 54 56 61 94 95 101 103 115 118 143 168 169 176 181 182 191 194 197 207 208 214 216 218 220 224 225 239 time 104 ultra fast data 96 UT 22 32 123 125 127 129 135 UTIL 34 42 50 71 72 75 76 82 83 93 95 102 117 131 145 152 158 162 5 22 99 Index 249 170 197 201 vacuum 14 16 29 125 126 172 179 181 194 223 226 World Wide Web 1 3 239
29. 888 e LLLI TIL LLL EL tall TT Sooo 1 R eee 21 ostat Inputs and Outputs 17 Cry 5 22 99 L j J M m M M M M M n 1 Output 9 2 wf af af wf af af sf sf af af of sf sf af 4 4 of v X l 5 5l 3l 5 3 5 5 5l 3l 3 amp 8 amp g S amp 5 2 o 6 6 6 6 5 2 5 2 5 5 5 02 s gt gt gt gt gt gt gt gt gt gt al f wl ol ol Sf 9 Sf 5 d el el af amp l Al ayo gt 4 6 8 5 o5 R al 3 3 2 2 2 2 2 2 5 5 5 5 5 5 5 Sf Of OF OF Of OF OF OF OF SG 5f Ss f 5 S 4 Sig Table 17 218 MIRAC User s Manual Table A17 5 Grounds and Array Temperature Sensor No Panel Cryost NOM Name Voltage Function Cable Conn Conn Ohms mm Sig A Sig Ret Package flr go ee rs nu Sig a e g Cryo Case Dig E F H 0 Cryo case 26 27 28 14 31 LH Notes pins 9 43 51 58 68 should be very low impedance to ground to minimize noise Combined resistance less than 10 Ohms Table A17 6 Array Resistance T
30. Alpha Sco Alpha Tau Beta And Beta Gem Beta Peg Epsilon Mus Eta Sgr Gamma Aql Gamma Cru Gamma Dra IRC 10216 Lambda Vel Mu Cep Mu UMa Sigma Lib MIRAC MIRAC MIRAC MIRAC Cohen Hanner MIRAC MIRAC Cohen MIRAC MIRAC MIRAC Cohen MIRAC Cohen MIRAC MIRAC MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC Cohen Hanner MIRAC MIRAC MIRAC Hanner MIRAC MIRAC MIRAC MIRAC MIRAC MIRAC MIRAC 19 48 02 04 05 12 14 13 06 22 06 42 07 36 17 12 09 25 18 35 05 52 16 26 04 33 01 06 07 42 23 01 12 15 18 14 19 43 12 28 17 55 09 45 09 06 21 42 10 19 15 01 8 44 23 13 45 56 19 26 52 40 16 38 05 21 14 26 08 26 38 44 07 23 26 19 16 24 35 21 28 08 27 48 67 41 36 46 10 29 56 50 51 30 13 31 43 14 58 33 41 45 25 05 2 505 1114 3184 9793 10161 2065 2143 2182 1124 15238 1883 1901 618 618 24600 18661 8146 8932 3334 3523 1686 1734 4775 5093 2285 2576 998 11348 2046 356 147 2824 1364 2264 Table A2 3 Standard Stars with Flux Density Alphabetical Order 2 3 8 203 468 1351 4310 4431 909 884 852 456 7560 806 852 243 243 15364 11655 3859 4041 1609 1565 735 749 2325 2369 1063 1165 490 5230 884 6116 48 6 2025 584 934 Wavelength um Janskys 4 8 7 9 8 8 9 8 103 131 608 495 402 36 5 274 125 101 801 728 925 35
31. File 0002 1 0 AIRMASS Size 32 x 20 File 0002 restored to IRAF File 1921210a 220 File 0080 1 0 AIRMASS Size 32 x 20 File a0080 restored to IRAF File i921210a 298 138 aaaaaaa VVVVV VY Dec 10 copy f copy f edit aml edit am2 l gt imcombine aml aml 117 combine average B95 combine 0 blank MIRAC User s Manual del f92 ls 192 2 imh gt flistl listl aml listl am2 7 average Images 1921210a 219 imh 1921210a 220 imh 1921210a 228 imh Output image aml 117 ncombine 10 cl gt imcombine am2 am2_117 combine average Dec 10 blank i combine 0 8 8 Images 1921210a 279 imh 1921210a 280 imh 1921210a 288 imh Output image am2_117 ncombine 10 cl imarith am2 117 aml 117 117 cl imstat 117 STDDEV MIN MAX 117 640 T8 25 01 16 28 251 7 cl displ 117 22 251 frame to be written into 1 4 2 21 Oe 2 Zooks cl gt imarith 117 187 0 117 cl imarith 1 0 117 117 gt imstat 117 STDDEV MIN MAX 117 640 195 0 1337 0 08704 1 346 cl imarith gainll7 0 5 117 pixtype short cl displ mask117 22 5 21 2 frame to be written into 1 4 2 212 2 Be
32. IL J StDevTable Header Page Values XHex Values MCAD format 5 22 99 13 Shipping Procedures and Shipping Inventory 163 Appendix 13 Shipping Procedures and Shipping Inventory A13 1 Shipping Procedures Shipping is with the SAO or other institution contract shipper currently Federal Express We use a third party charge to a FedEx account For SAO the approval for this and the account number is obtained from Leslie Feldman at SAO 617 495 7428 email feldman cfa harvard edu It is best to ship Monday allowing 5 working days for the shipment Three working days are normally required The crates should be transported to and from the Federal Express facility by UA or observatory personnel to avoid damage from local truckers Airbill Instructions 1 From address and phone number of shipper below Internal Billing Reference Obtain from party paying for the shipment 3 To address and phone number of destination below also address of destination Fed Ex office to be held at below Check Hold Weekday Hold Saturday 4 Check FedEx 2Day Ab Nothing checked 5 Check Other Package 6 Nothing checked 7 Payment Check Third Party Fed Ex Account No Obtain from party paying for the shipment Credit card number leave blank 8 Items total 790 165 Each item is within standard Fedex weight and size limit Confirm number of items and hold destination at Fedex depot Federal Express Information and Tr
33. Take three sets of data 1 Radiation source through the polystyrene OBS Next Object Name CVF Cal w Polystyrene OBS Header Filter Init Filters First wheel CVF Start Run 2 Radiation source direct Slide the sample out of the beam OBS Next Object Name Hot source direct OBS Header Filter First wheel CFV Start Run 3 Room temperature radiation Place cardboard between radiation source and mask OBS Next Object Name Room temperature OBS Header Filter First wheel CFV Start Run OBS Next Save off This gives three sets of 200 files one without the sample one with the hot source and one of the room temperature background 4 Reduction of data Create three ASCII files of the mean flux for each of the sets of files above The following will create an ASCII file with a line for each input image with obs wavelength and skyflux UTIL Functi Output ASCII files Skyflux Output file name WITHPOLY TXT 118 MIRAC User s Manual Data file string file range Begin output Import these three files into a spreadsheet such as Excel along with the reference Beckman Spectrophotometer scans of the polystyrene sample The polystyrene absorption is the source with polystyrene minus the room temperature card divided by the source direct Previous examples with Supercalc cal files and Excel xls files are in MIRAC PC in the directory c cvf The calibration process is to determine a scale and shift correction to the waveleng
34. Telescope nod ETHERNET IRTF UKIRT RS232 UKIRT SO RS232 S O 90 inch Telescope offset Same as above Nod beam control MIRAC generated nod off IRTF S O on UKIRT with MIRAC nod Guiding no guiding RTF UKIRT with no guiding main beam UKIRT guided w MIRAC nod or both beams d RA nod vector set for UKIRT Dec nod vector d Offset control parameters Command tel offsets on Mode of offsets absolute Offset delay ms 2000 UKIRT with guiding 5000 w o guiding 4000 Anti bklsh offsets off RA Abklsh 0 Dec Abklsh 0 Abklsh delay 0 Tel offset mode No guiding w o guiding Guided offset IRTF UKIRT w guiding Other Nod and chop parameters are covered in Section 6 1 Nightly startup tasks Item 9 16 Check display settings NOTE The macro F6 Dispparm can be used to make all the following settings Disp Init 5 22 99 5 Start and End of Run Setup and Shutdown Check Lists 25 of Display Array Stats and Fit Stats On Fit Gaussian Region Full Map Invert Off Auto Range Settings Autorange mode MinMax Noise min factor 2 Max Noise factor 5 Orientation for camera window North East Horizontal flip on off Vertical flip on on Transpose off on Direction on North up East left Magnified image on Width Display FWHM Display on Small Display Limit 0 Large Disp Limit 5 Number for running ave 5 Arcsec Grid Display Arcsec grid lines On Grid spacing 5 Color Screen Mode Heat SVGA Force B W Mod
35. Weather and Tau Information from the Web A22 1 Arizona Weather Information Weather information and satellite images for Arizona observatory sites can be obtained from Steward Observatory http www as arizona edu Steward Observatory Facilities Telescope Schedules Observers Home Page Observing Information Weather A22 2 Mt Graham Tau Meter Data A variety of weather information satellite photos and submm transmission can be obtained from Steward Observatory http www as arizona edu Specific Projects Sub millimeter Telescope Observatory Local Weather Atmospheric Conditions at the SMTO A22 3 Mauna Kea Weather Information from University of Hawaii The best source for images of Hawaiian weather is IR GOES images http lumahai soest hawaii edu gifs hawaii_ir gif Visible light images http lumahai soest hawati edu gifs hawaii_vis gif These are updated hourly and show a few hundred miles around the islands A22 4 Mauna Kea Weather Information from the Gemini Home Page The Gemini WWW home page gives access to daily photos of the Gemini construction site UKIRT current conditions and many weather satellite pictures http www gemini edu Construction and Operations Photo gallery Daily Construction Pictures from Mauna Kea Current conditions A22 5 UKIRT Weather Information for Mauna Kea The current temperature windspeed wind direction pressure and humidity at the UKIRT dome can be retrieved from the World Wide
36. ee gow a Be 81 11 1 6 Multiple Image 82 11 1 7 Processed Images 83 1 1 8 NOIE ata dite dee E RR E E E E A FAR RR E ERE VE 83 11 2 2Display Mod s RO eA RO ae BR 83 DI 2D Grayscale STE 84 11 2 2 Contour 4 12922 9 s ESAE TEE 84 yy 85 NE sicui PC 86 L1 2 3 Hist gtam en uc da orsa RV ga a UP TIU an Ea oa SA Ea 86 11 2 6 Radial Plot so sasi orient SER 87 11 2 7 Plot Command Line Options 88 LES Sep a IUS se n d 88 TO Redraw qu eue a SCR urat coo Rag di Rios ur 89 Fit essct 89 L2 7E EE EUR ed ee d 90 T2 ae ee a ee ee 90 56 EAFOOODy ten 66 270 Hcet esee Eee Ee utes 91 11 277 O tpUt oos e edo 91 12 Utiles es Sou ple Se toa Coe AVR So eet oe 93 12 1 SS COpe DIS play Sedo rd edoceri elk Sana deor Gear kha nt Sosa UR 93 12 2 Temperature and Heater Monitor
37. proper orientation in any of the display modes other than the main image display screen such as in the Contour Grayscale etc the image must be flipped here Contrary to the flip options in DISP INIT these options change the position of the data in the array rather than just choosing which direction to plot the data so if the current image is saved it will be saved in the flipped mode If the directions are set such that N is at the top and E is at the left the same flips necessary in DISP INIT must be performed on the image For example if using MOSAIC to create an image and the X flip is necessary to display the data with N at top and E on the left then the X flip must be performed on the image to correctly orient the image Transpose This exchanges rows and columns 5 22 99 13 Post Processing Images 99 13 Post Processing Images Much of the simple data reduction can be performed on the MIRAC computer but usually the final reduction will be done on a VAX or on a Sun using IRAF The advantages are the increased computing power disk and tape storage space and the capabilities of the image processing software that has been written for these computers 13 1 Converting files to FITS format The files must first be put into a format that these processing programs can easily read This is done by converting to FITS format either after transferring to another computer or by converting them on the PC before transferring 13 1 1
38. such as int5 Example of Command file JUPMAIN CMD FILTER CVF 13 30 EM FRAME33 EM INTI RUN FILTER CVF 10 74 PAUSE 5 RUN FILTER CVF 8 57 PAUSE 5 EM FRAME70 RUN FILTER CVF 7 85 PAUSE 5 EM 5 RUN RUN RUN FILTER 17 4Q0 PAUSE 5 EM INTI EM FRAME 7 RUN RUN FILTER 17 801 PAUSE 5 RUN RUN FILTER 20 6Q3 PAUSE 5 EM 5 EM FRAMES RUN RUN END 46 MIRAC User s Manual 7 6 Offset Files Offset files are text files created and edited with any text editor such as DOS edit Each line contains RA and Dec offset in arcsec The MIRAC pixel scale and field size are given in Table 2 1 Offset files in the observing directory can be listed from the DOS prompt with dir off and displayed or edited with type or edit When Obs Next ReadOffsets is and Run is executed the telescope is successively moved to each offset position followed by How Many observations at that position Generally the last offset is zero in order to facilitate checking pointing and tracking Examples of offset files are 5 for measuring focal plane scale at IRTF and 90 inch with four points in corners of array ending at center 1414 1414 14 14 14 14 00 UKIRT5 OFF for measuring focal plane scale at UKIRT with four points in corners of array ending at center 11 11 11 11 11 11 11 11 00 MMTS5 OFF for measuring focal plane scale at f 15 with four points in corners of array ending at
39. the location of a function will be described by its position in the MIRAC menus The position is specified by giving the name of the top line command menu followed by the submenu under it For example to indicate the location of the command to set the integration time is located in the OBS command line Header command submenu Observation parameters This is indicated by the following shorthand notation OBS Header Observing Parameters The top line menu is given followed by a colon and the submenus indicated by slashes The OBS Next menu is illustrated in Figure 9 2 with typical settings Note when camera parameters are changed the program pauses after Run is executed before starting a new observation 66 MIRAC User s Manual The Alt M key and Function keys are used to control the definition and execution of macros This is described in Section 7 4 9 6 Selecting Display Modes and Options The display mode is set in DISP Load Mode The desired mode for displaying current observations as they are being made is current Other modes are discussed in Chapter 11 Display options are set in DISP Init Statistics options are selected in DISP Init Stats and Fit Parameters Fit Function provides for enabling and choosing a source fit function Object Detection Sigma gives the threshold in noise sigma for automatic detection of a signal above the mean background The mean background and background noise sigma are determined iteratively from the pi
40. two captive screws with a 3 16 ball driver 5 Mount the camera electronics on the cryostat The electronics should first be inspected for loose screws properly seated circuit boards and any other sign of a problem The electronics mates to the dewar with a self aligning bracket Insert and tighten the two knurled head captive screws on the bottom Insert and tighten two 8 32 x 3 4 screws on top with a 5 32 allen wrench 6 Use tubing with quick disconnect fitting to run dry air from east side of telescope mounting flange to cryostat window S O 2 3 m telescope Air dryer power and control valve are in room on east side of observing floor L MOUNTING FLANGE GUIDER IESU BOX si CAMERA ELECTRONICS ji CONTROLLER FILTER 0 WEDGED SLIDE 20 Inches Figure A14 5 MIRAC Camera Mounted on Telescope 5 22 99 TEMPERATURE SENSOR HEATER FILTER CONTROLLER 5 252 14 Hardware Preparation and Setup a SIGNAL CHOPPER POWER DETECTOR RAME NITOR BIAS DATA COMMAND TEMPERATURE MONITOR FIBER OPTIC 12 5 gt POWER O POWER GND LOCAL Remote
41. 01 3 08 1 9 5 2 1 5 1 39 0 7 1 19 1 25 1 74 1 3 7 6 0 96 1 72 3 38 3 15 3 19 1 6 4 5 3 93 1 45 1 7 0 78 0 82 4 3 2 51 2 53 N 2 05 3 02 1 35 1 22 1 31 3 14 2 44 11 7 2 18 2 11 2 15 0 76 3 05 3 07 3 12 1 9 5 5 1 45 1 39 1 35 0 7 1 22 1 22 1 26 1 78 1 26 1 35 7 6 1 1 1 66 3 44 3 21 3 16 3 2 1 6 4 7 4 1 1 5 1 75 0 0 0 8 0 84 0 4 2 2 49 2 51 2 55 12 5 2 18 2 16 0 77 3 07 3 12 1 9 5 5 1 53 1 35 0 73 1 19 1 27 1 8 1 4 8 1 1 1 59 3 45 3 23 3 2 1 6 4 7 4 16 1 5 1 79 0 8 0 84 0 05 4 04 2 51 2 55 13 5 2 1 0 78 3 07 1 9 5 5 1 53 1 31 0 73 1 19 1 8 1 4 8 1 1 1 59 3 45 3 23 1 6 4 8 4 3 1 7 1 79 0 82 0 1 4 1 17 4 2 1 0 83 3 08 1 9 5 75 1 32 1 41 0 7 1 21 1 8 1 5 8 4 1 3 1 9 3 45 3 2 2 4 8 4 3 1 7 1 8 0 82 0 2 4 7 17 8 0 83 3 08 1 9 5 75 1 32 1 41 0 7 1 21 1 8 1 4 8 4 1 3 1 9 3 45 3 2 4 8 4 3 1 7 1 8 0 82 0 2 4 7 0 83 3 08 1 9 5 75 1 32 1 41 0 7 1 21 1 8 1 4 8 4 1 3 1 9 3 45 3 2 4 8 4 3 1 7 1 8 0 82 0 2 4 7 20 6 0 83 3 08 1 9 5 75 1 32 1 41 0 7 1 21
42. 05 1 22 2 44 5 5 4 7 3 05 3 07 3 12 2 18 2 11 2 15 1 22 1 22 1 26 2 51 2 49 2 55 1 66 1 75 0 8 0 84 3 44 1 5 7 6 1 78 4 2 1 1 1 6 12 5 0 05 0 77 1 9 3 23 3 2 1 53 1 35 0 73 4 16 1 4 0 5 5 4 7 3 07 3 12 2 18 2 16 1 19 1 27 2 51 2 55 1 59 1 79 0 8 0 84 3 45 1 5 8 1 8 4 04 1 1 1 6 13 5 0 1 0 78 1 9 3 23 1 53 1 31 0 73 4 3 1 4 5 5 4 8 3 07 1 19 2 6 1 59 1 79 0 82 3 45 1 7 8 1 8 4 1 1 1 1 6 17 4 0 2 0 83 1 9 3 2 1 32 1 41 0 7 43 1 5 5 75 4 8 3 08 1 21 1 9 1 8 0 82 3 45 1 7 8 4 1 8 4 7 1 3 2 17 8 0 2 0 83 1 9 3 2 1 32 1 41 0 7 4 3 1 4 5 75 4 8 3 08 1 21 1 9 1 8 0 82 3 45 1 7 8 4 1 8 4 7 1 3 18 0 2 0 83 1 9 3 2 1 32 1 41 0 7 4 3 1 4 5 75 4 8 3 08 1 21 1 9 1 8 0 82 3 45 1 7 8 4 1 8 4 7 1 3 20 6 0 2 0 83 1 9 3 2 1 32 1 41 0 7 4 3 1 4 5 75 4 8 3 08 1 21 1 9 1 8 0 82 3 45 1 7 8 4 1 8 4 8 1 3 2 3 16 1 34 1 35 3 08 2 12 1 23 2 51 66 4 57 sms 601 Alpha Aql Alpha Ari Alpha Aur Alpha Boo Alpha Car Alpha CMa Alpha CMi Alpha Her Alpha Hya Alpha Lyr Alpha Ori
43. 1 NOD WAIT IME SEC NODOFFWT 3 000000000000e 00 NOD WAI TIME FOR BEAM 2 MAGNIFIC 4 382812380791e 01 MAGNIFICATION SETTING DETBIAS 2 000000000000 00 DETECTOR BIAS VOLTS HEATERV 1 427913784981 00 HEATER VOLTAGE DE MP 5 370593547821e 00 DETECTOR TEMP K 432 TOTAL COADDS IN EACH BEAM ELESCLE 1 870000004768e 00 PIXEL SCALE ARCSEC MM INITX 1 X START PIXEL INITY 1 Y START PIXEL ENDX 128 X END PIXE ENDY 128 Y END PIXEL OFFSET1 0 000000000000 00 X OFFSET PIXELS OFFSET2 0 000000000000e 00 Y OFFSET PIXELS ARRAYXSZ 128 X ARRAY SIZE ARRAYYSZ 128 Y ARRAY SIZE MASKFILE 0 1lab1020 msk OBSMODE 3 OBSERVING MODE CHOP NOD FILENAME c981115a 520 SAMPMODE O 0 SINGLE SAMPLE MODE DELAYCYC 0 DELAY CYCLES CLOCKRAT 0 CLOCK FREQUENCY 15 6 2 N HZ COPERCHP 1 COIMAGES PER CHOP CYCLE 136 MIRAC User s Manual
44. 103 104 136 147 183 191 197 200 210 COCK Sy eck e Eo 205 206 209 210 Bel aede 141 210 211 column 50 82 83 85 86 93 95 97 101 121 132 133 135 147 154 155 159 161 197 199 207 209 command file 35 39 42 45 56 117 146 150 constant 9 74 89 97 148 159 210 contour 79 83 85 89 90 98 155 157 161 conversion 94 96 99 100 107 131 136 158 208 cryogen 13 15 17 31 125 180 182 183 185 196 203 cryostat 3 5 11 14 16 17 24 26 29 31 37 116 118 125 126 164 168 170 172 176 179 183 185 186 191 192 194 196 203 206 213 214 223 226 current observation 44 53 64 71 79 80 150 CURRENT HDR 31 33 35 59 144 145 6 7 10 41 43 45 59 67 106 116 118 146 147 149 150 236 237 data file directory 32 79 144 159 data format 33 79 96 153 246 MIRAC User s Manual datel9 22 31 32 35 60 64 76 77 81 95 125 129 135 144 227 229 235 xEWSRREXSEREEAG 19 124 136 200 default directory 45 59 79 143 default display 83 97 detector4 7 9 11 26 31 33 54 60 61 63 75 78 94 95 101 103 104 135 148 173 175 176 179 182 193 194 196 207 208 213 216 224 225 dichroic 26 49 93 94 125 127 196 199 directory 19 21 23 25 32 36 42 45 46 50 53 54 56 59 60 67 75 77 79 93 95 96 101 11
45. 17 19 20 22 24 31 32 34 40 41 46 49 54 72 73 104 112 119 121 126 143 144 147 149 164 167 170 179 182 186 188 190 194 196 198 201 203 223 236 242 JUSTY 82 97 229 Kitt Peak 11 14 124 149 241 laser printer 21 119 191 Leve 23 24 31 33 39 40 54 62 65 66 68 72 75 78 80 85 89 90 94 117 125 126 147 152 155 157 166 168 174 177 182 183 191 197 199 200 208 214 230 LHe 14 15 28 29 115 125 126 168 169 172 176 177 180 183 203 220 223 226 linear 3 7 8 10 40 41 56 62 63 70 76 78 88 89 117 136 148 197 207 208 214 Ln2 15 16 28 29 53 57 126 136 168 169 172 179 183 193 194 197 203 220 223 226 log file 56 57 73 97 145 158 159 237 macro 23 24 32 33 40 42 43 50 59 144 158 160 233 237 magnification 4 6 10 24 41 59 67 74 78 125 127 135 148 172 179 180 194 197 201 223 mask 6 22 23 33 40 59 61 72 75 77 79 80 93 99 116 117 127 132 137 138 141 144 153 174 201 224 mask file 127 132 138 141 menu 19 21 22 31 34 39 40 42 45 53 54 59 62 64 68 74 77 79 81 83 84 88 89 93 94 96 101 160 196 197 200 201 235 236 MIRAC program 19 21 31 33 35 53 59 64 67 68 73 96 101 119 125 143 170 181 200 201 mode 4 9 10 23 25 33 35 39 41 43 45
46. 3 which are multiplexed to 16 output MOSFET source followers by fast column and a slow row shift registers and switching MOSFETS Current from a detector pixel is integrated on the capacitor Cwr and read out through a source follower The capacitor is reset through a reset MOSFET The detector input node is isolated from the integration capacitor by a direct injection MOSFET which allows a large linear output voltage swing across the integration capacitor without affecting detector bias 208 MIRAC User s Manual SELECT Row 16 VRST VACC VDD HL D as DETSUB r r r SELECT COL 1 SELECTCOL64 RESET COL 1 VDI SIGNAL OUT CUR 16 ea R CUR_S VSOU Figure A16 3 Boeing HF 16 Si As array unit cell The array signals at the source follower outputs are in the range 4 4 to 2 1 V from reset to full well The preamp shifts the voltage to center it in the A D range and applies a gain of 4 At this gain the range of the A D is less than the range of the array output Four voltage offsets commanded by OBS Header Flux Level Low Medium High and Variable provide for covering from below zero flux to medium flux from low flux through the linear range and from above medium flux through saturation respectively within the 2 5 V 2048 A D range The same commands control a software offset which shifts the digital output for each range so that on the P
47. 48 50 59 61 64 66 74 76 78 87 89 91 93 95 98 100 102 104 117 120 122 129 131 132 135 136 247 143 146 150 155 161 162 194 199 200 208 210 214 229 mosaic 60 64 75 81 98 101 143 154 motor controller 67 170 176 50 77 81 97 nitrogen 15 17 136 173 180 183 193 nod 4 6 9 11 24 32 35 39 40 42 43 47 50 55 56 60 63 66 68 73 75 76 79 95 97 99 101 104 117 125 127 129 131 135 146 147 150 151 191 200 201 noise 3 7 11 25 41 47 62 63 66 75 77 78 80 83 97 101 103 105 125 129 144 152 154 208 218 object 19 23 33 35 39 40 42 43 47 50 55 56 64 66 74 76 77 80 103 117 119 123 125 129 133 135 147 172 177 object list A ERA es 120 OBS 19 21 23 24 31 35 39 46 48 59 62 65 68 71 73 74 76 82 93 94 101 102 117 119 129 135 144 146 150 152 155 158 161 162 164 183 191 194 196 197 200 201 206 208 241 observation 1 9 11 42 44 49 53 60 62 64 65 67 68 71 75 T1 79 81 95 101 105 131 133 135 136 150 OBSLIST 19 119 120 122 143 144 offset file 39 40 44 56 117 150 151 Offsets 9 23 24 35 39 42 44 50 62 73 74 77 80 81 83 105 125 141 146 151 200 201 208 220 offsetting modes 74 on source 49 50 68 70 76 105 operation 42 50
48. 603 6 8 W2 CVF 7 7 14 5 um W1 P Home all wheels W2 A12 1 5 OBS Wait observation with Current Abort observing and coimaging Stop continuous coimaging L 12 1 6 OBS Save Save Options Save All Off Current image save Next file number ili Data file dir d d941229 Backup data Dir i d941229 Make FITS file of current obs Grab Chop Chop Nod Nod 2beam Nod 4beam C H EQ Hl El O OQ 0 print savefits findstar stdparm objparmn dispparm None defined None defined None defined savrdrun 5 22 99 12 1 OBS Command Line Menus 151 A12 1 7 OBS Telesc A RA Offset 0 000 B Dec Offset 0 000 C Offset Row 0 000 D Offset Col 0 000 Load Next Offset from File Reset Offset file Telescope Control gt Telescope Control 4 A Tele NOD Ethernet B Tele OFFSET Ethernet Nod Beam Control gt Position Commands gt Guide amp Track commands gt Offset control params gt Define current pos as zero SO RS232 PLUSPULS NEGPULSE LEVEL U ANUAL Ethernet KIRT RS232 Move to next Move to referenc Move to current plus offset RA offset DEC offset Move to offset 0 0 Motion CANCEL Clear Diff TaI W Guide
49. 64 73 75 79 80 82 83 94 100 102 154 193 197 206 207 214 orientation 25 29 61 66 78 83 89 96 98 125 127 132 136 157 199 201 Output 8 68 72 91 93 96 99 117 124 131 132 137 139 141 156 159 162 191 194 201 207 208 210 211 214 229 233 235 64 Page BS ar ma gt 65 248 MIRAC User s Manual PC3 4 19 21 23 26 31 33 34 36 44 55 57 59 60 64 67 71 73 94 95 99 100 102 118 119 122 124 131 133 136 143 170 175 183 185 188 191 199 200 205 208 211 235 237 performance 1 3 94 personnel vo 163 PHONE ics 163 165 227 243 plate scale 1 as 74 201 plot 23 59 61 62 83 90 93 98 115 116 137 144 155 157 161 179 181 power cable 28 191 192 205 power supply6 31 33 37 54 56 164 169 175 176 181 188 191 192 205 221 222 POWER UD a usa humus 26 33 print 19 25 42 44 50 51 66 88 91 120 121 144 150 157 160 162 227 228 230 232 233 printers 25 42 59 101 143 162 PRINTERS DAT 143 162 prn nib 28 65 ose eme RES 21 143 processed map oos ove 79 PS Eu oiu SO ERG Rar eA 105 pupil 4 49 127 136 147 148 167 170 172 179 180 194 197 200 223 ood bnc
50. 8 252 Figure A14 6 Camera Electronics Connector Positions 14 6 Cabling and Connections 187 22 75 If the camera has been shipped and there is any indication of rough treatment of cables these should first be checked for damage by visual inspection of the connectors and by testing with a resistance meter for continuity and shorts This is especially true of the power and camera clock cables 188 MIRAC User s Manual Laying Out the Cable The cables from the control room to the telescope are laced together to make a single cable bundle 120 feet long Each end has a protective sheath for the connectors The power connectors are plugged into dummy mating connectors for additional protection The cable bundle is coiled in the cable crate 3 with the camera end at the bottom with 12 feet free for access without removing the entire cable from the crate during lab testing The cable bundle is loaded into and removed from the crate using dolly with swiveling casters so that the crate forms a reel which is rotated allowing the cable to be removed without kinking During the reeling the excess twelve feet camera end of cable is wrapped 3 4 turn around the outside of the crate hung from the crate latches It is essential to take extreme care not to damage the cables or connectors while loading and removing the cable The cable should be removed from the crate in the telescope chamber The control room end which comes out of t
51. Camera Power Supply The camera power supply voltages and currents are given in Appendix 18 and on the power supply panel When turning on the power supply it is a good idea to watch all the green indicator lights come on and to note that none of them dim when the delay relay closure connects the camera to the supplies The supply voltages and currents can be monitored using the three banana jacks on the power supply panel The two left hand jacks used with a millivolt meter give the current The middle and right jack give the voltage The voltages and currents should be checked if there is any indication of a problem The power supply relay and voltages can be checked without the camera and with or without the power cable by inserting the dummy mating connector either at the power supply or at the camera end of the power cable This should be done if there is a suspicion of a power supply or power cable problem A16 3 Fiber Optic Command and Data Link When the command and data links are properly operating the data link LED lignt at the MIRAC PC and the command link LED at the camera will both be on steadily If either of these are off or are intermittent the fiber optic cable should be checked for damage and the ends cleaned with a Q tip and alcohol 16 4 Biases and Clocks The biases can be monitored with the bias monitor board plugged into the socket at the edge of the bias box in the camera electronics or at the digital connector using
52. Converting using a unix computer The most commonly used way to reduce MIRAC files is to transfer them to a Unix computer and convert them to FITS format using the C program mrc2fts described in Appendix 7 This program can combine the chop nod images apply a mask and a gain map and expand the format Then these files can be further converted for processing with IRAF as described in Appendix 10 13 1 2 Using the MIRAC3 program to convert to FITS The conversion process is described above in Section 12 5 This process reads in the data files from the PC does the necessary subtracting of off source frames masking subtracts the flat field and multiplies by the gain map if selected The images can be expanded by powers of 2 for later registration to the nearest subpixel This process is less commonly used since it is more efficient to transfer the smaller MIRAC3 formatted files and expand them on the workstation to be used for most of the data reduction Also the PC program is slower in performing this step compared to most workstations 13 2 Transferring files Using PC NFS the transfer of the data is simple Assuming that one is using the MIRAC3 program to convert the files and has mounted a disk drive on a remote computer and that drive has been designated as one simply sets the output file name in the FITS utility as I F920313A for example Then the FITS files are written directly to the remote drive in the proper format If the MI
53. Offset Select Offset source Header Header Calculation mode None User Input Offset file name File Expansion factor 1 Calculate Enter data file string Headr File E Sou rce o Data file string al a10 Force Zero Averag Off Verify every offset Off Calculation Radius of centroid region 2 Use flat expand Off None Begin Mosaic Shift peak Centroid mode Ji Operation Mode F Performing operation Enter the operation below d d940805 c940805b 228 b229 2 LL REPLAY Setup Frame number 0 Input files al a10 Pause after each image Off Begin display Noise Display Enter the column to display 1 Enter the files al al0 l i 5 22 99 12 2 DISP Command Line Menus 155 A12 2 3 DISP Header Same Menus as OBS Header A12 2 4 DISP Begin Display Image iL WIL Displ Map Plot mode Contour Slice direction Column Contour Parameters gt Gray Plot Params Edit gt directio 77 Row Column J p Contour Parameters Num contour levels 12 Auto contour levels Off Enter contour levels Plot params edit L al 1 Params Edit Display Size Limits Style gt Labels of plot gt Contour
54. Plots Figure A3 1 gives plots of the MIRAC3 N Band filters and atmospheric transmission Figure A3 2 gives plots of the MIRAC3 Q band filters and atmospheric transmission The filters marked M are made by the University of Reading The filter characteristics are taken from the Michelle contract specifications for 25 K temperature The filters marked Q are made by the British firm FK Optical US representative ORT The measurements are taken from FK Optical measurements at room temperature corrected for LHe temperature by multiplying by 1 029 The atmospheric transmission data comes from Glenn Orton Figure A3 1 Plot of N band filter and atmospheric transmission 116 MIRAC User s Manual 0 8 1 0 7 0 6 c E 5 0 5 b 0 2 L S 0 4 M E 0 3 4 o 0 2 0 1 L 0 14 Wavelength microns Figure 3 2 Plot of MIRAC3 Q band filter and atmospheric transmission A3 2 CVF Calibration The CVF wavelength calibration requires determining a scale wavelength increment per filter wheel stepper motor step and an offset relative to the home position of the filter wheel The first should be very stable The second can change if the CVF is removed from the filter wheel the home switch cam on the filter wheel adjusted or the home switches support post moved The two parameters can be determined by scanning the CVF looking through a calibrated polystyrene sample sold by Beckman for this pur
55. RUN command The case of the commands is irrelevant all commands are converted to uppercase before executing commands are issued immediately after reading it from the file except for the RUN and WAIT commands those commands cause the program to wait until the current observation or series of observations are complete before executing the next line of the command file While the command file is executing the program will respond to user input during the wait period while an integration is going on Caution should be used however that one does not do something that will disrupt the command file execution For example if one did an OBS Next Dos Shell the program could not complete the observation Also all commands in the command file must execute from the OBS main menu so if one happened to be somewhere in the program where it couldnt reach the main menu easily the commands would not be executed properly The safest approach is to avoid doing anything while the command file is executing It is possible to hold or stop a command file execution One way it can happen automatically is if an unexpected error is encountered such as an invalid command in the command file or if some file is not found etc The program displays a warning message with the error then stops command file execution The user can also manually halt or hold execution of the command file If an observation is in progress the user can use the OBS Wait Hold command
56. Refres Clear Save OBS UTIL PRN Quit Obs Mode Grab Log Sav On Off 0 50 Filtr 1 8 8 pn Chop Hz5 4 92 amp AMBTemp 189 37 Off Dec 0 50 Filtr 2 Open FrTime ms 4 369 LN2Temp 312 51 EleTenp 189 37 Filtr 3 Open IntTimecs 0 28 DetTemp 297 890 A DTemp 189 37 Wavelth 8 80 3500 4500 i112 Section Full Map i T Data Max 2033 75 lt 12 36 Dmin 1202 63 lt 5 121 Fit Max 0 00 lt 0 00 0 00 gt FWHM 0 00 ChiSa 0 000 Total RMS 356 41735 Avg 2 7779 Num 16384 Background RMS 356 41735 Avg 2 7779 Num 16384 Source Sum 0 0 Num lt 05 Sky Flux 3370 8 RMS 1 24 DIF 0 7 Limits A D lt 5415 1320 FrameErrors o Flux MaxMin 5402 2165 BLIP 99 00 Lev Medium OutOfRange 3 0 gt OBS 5 14 99 15 47 28 990514 007 UY AUR IDLE 0 00 0 00 0710000 DISP 5 14 99 14 18 10 45 d test9905 c990514a 005 UY AUR Mode Replay Figure A16 2 The MIRAC Main Screen with the detector at room temperature A16 7 Array Operation The material in this and the next sections is taken from 2 a mid infrared array camera for astronomy W F Hoffmann J L Hora G G Fazio L K Deutsch and A Dayal Proc SPIE Infrared Astronomical Instrumentation 3354 647 1998 The HF 16 is a hybrid array with the Blocked Impurity Band BIB detector bump bonded to a large scale integrated circuit readout chip The array readout contains a unit cell circuit for each of the pixels Figure A16
57. Table A14 1 The overall cryogen consumption is given in Table A14 2 The LHe hold time for the cryostat vertical and unpowered is longer on a mountain top than in the lab because of the lower LN2 temperature at the lower atmospheric pressure The LHe hold time is reduced when the LN2 slide is opened and the array powered It is reduced considerably more when the cryostat is tilted due both to loss of cryogen if the reservoirs are nearly full and convection in the LHe neck tube Table A14 1 Cryostat Capacity and Hold Time Hold Time hours Capacity Level inches Fraction Fraction Quiescent Operating liters Full Empty Remaining 60 Tilt Lab Obs Lab Obs LN2 27 24 57 0 30 x 5 7 level 90 36 36 36 36 LHe 3 7 T2 11 9 0 22 x 11 9 level 67 40 42 36 38 Table A14 2 Cryogen Consumption Item Liquid Nitrogen Liquid Helium Cooldown 24 hrs 12 liter 8 liter Per Day 4 liter 4 liter IRTF 6 Days Require 32 liter 28 liter IRTF 6 Days Request 35 liter 40 liter Storage dewar daily loss not included 184 MIRAC User s Manual A14 4 Control Room Setup The control room layout for MIRAC 15 shown in Figure A14 3 At the S O 2 3 m telescope the PC should be located to the right of the Sun workstation near the telescope monitors This makes it easy for the MIRAC observer to see the TV guide camera and telescope control system TCS monitor The A D interface box should be located nearby wherever it is convenient At the S O 2 3 m telescop
58. The MIRAC thermocouple gauge controller should be used with the thermocouple gauge mounted on the cryostat to monitor the cryostat vacuum If the pressure is greater than 100 millitor um a roughing pump should be used to reduce the pressure to less than 50 millitor before pumping with a diffusion vacuum system In such case the cryostat vacuum valve should be opened very slowly to avoid large pressure differentials in the cryostat After the cryostat is opened it should be pumped with a diffusion pump for several days even weeks before cooling down The cryostat vacuum should go to less than 1 millitor Thereafter the cryostat will continue to outgas and must be pumped again before each cooldown At the IRTF and UKIRT it should be pumped overnight using a turbo vacuum pump Generally the cryostat pressure rises to about 150 um after a cool down and warm up cycle Occasionally the molecular sieve on the LN shield should be vacuum baked at 60 C Figure 14 1 shows a plot of a typical pump down after the cryostat has been opened based on readings of the cryostat thermocouple gauge 180 MIRAC User s Manual 10000 1000 4 100 Pressure mtorr 10 lt gt 1 0 00 0 50 1 00 150 200 250 300 Time Days Figure A14 1 Cryostat Vacuum Pumpdown A14 3 3 Liquid Nitrogen Cool Down Before starting the L
59. Using the MIRAC Program 53 S General Notes da ge Ven ENSE CORP eo oA BTS M go 53 8 2 Starting MIRAC ON M EXE Aw ES 53 8 3 Observing with MIRAC cine kd keds Gace ha e whe See ie 55 8 4 Shutting Down MIRAC 2 5255 ERRARE ANE YE ARE 56 9 Using the MIB AC Progra siere suga ved RESTER Ro f 59 9 1 Running the MIRAC Program on a PC Stand Alone 59 9 2 Directory Str cture i sd exce race eor e a ise 59 9 3 Data File Name Conventions 60 9 4 Main Screen Display voce C ERE VAN RD SNE 60 9 5 Using MIRAC Menus and Functions 64 9 6 Selecting Display Modes and Options 66 9 7 Setting Camera Parameters and Taking Data 66 9 8 Filter Wheel Initialization and Motion 67 9 9 Observing Modes and 67 9 9 1 Source Frames and Off source Beam 68 ioo aeo eH Re 68 9 9 4 2 Chop oec ve ene RE SN 68 2 9 153 C BOpINQUSS 522 Nora rado dedere dic pe o Spa eor ca CS 68 9 0 1 4 Nod 2 beam 5 SIE Sa eau 70 9 9 1 5 Nod d beam eee odo eoe vere v eia e 70 99
60. about 20 nsec characteristic of the CMOS chips used LSYNC transitions occur at the rising edge of the FSTCLK wave form The rising transition of FSYNC occurs at the rising edge of LSYNC To provide proper synchronization of the shift registers and minimum reset time FSYNC must be greater than one LSYNC cycle and less than Gas two LSYNC cycles Reset is 1092 usec inhibited when the reset T MOSFET drain voltage VDDR gt LINE SYNC UU UUUTTUULU UU LUI UU UTI FRAMESYNC is low proper Inhibit Reset synchronization for the burst RESET CTRL VDDR VDDR transiti s 2 FSTCLK cycles after FSYNC start mode described below the EID reb PCIE epe VORA Ta ETEN falling edge of FSYNC must or 25 is T36 O39 occur two FSTCLK cycles after Line Sync Cycles one full LSYNC cycle The burst bode is achievediby Figure A16 6 Array timing with reset control for burst mode using the reset MOSFET switch drain bias VDDR as a clock to inhibit the reset during multi read integration as shown in Figure A16 6 To achieve proper synchronization the VDDR transitions must occur two FSTCLK cycles after the rising transition of FSYNC The array is clocked continuously and VDDR held low to inhibit reset for some number of array reads during which the charge in the array builds up For the example in Figure 6 reset is inhibited for just one read
61. adapter 9 pin male to 25 pin female Duct tape Clear packaging tape Aluminum tape Computer monitor swivel Clipboard for Observing Log sheets CRATE7 CRYOSTAT Gray Polypropylene 40x22x26h 103 Ibs 05 22 99 Cryostat with mounting plate with captured mounting screws aluminum plate window cover LN2 and LHe vent fittings with tubes electronics box mounting screws 2 10 32 x 1 socket head inserted in mounting Connector caps with conducting foam should be on cryostat signal and clock connectors Pupil slide should be in f 15 position maximum stop size Magnification slide should be in 0 43 magnification position and actuator should be left engaged LN2 shutter should be open LN shutter actuator and pupil actuator should be withdrawn from the cryostat Top ethafoam protecting cover and bottom octagonal box protector should be in place and cryostat enclosed in cardboard protective sheath and plastic bag window up Cryostat weighs 45 Ibs and is 28 inches tall Rubber vacuum hose with two hose clamps 1 2 inch ID 8 inch length CRATE 8 SUPPORT EQUIPMENT Gray Polypropylene 40x22x26h 103 Ibs 05 22 99 Hotplate IR source usually not needed not packed Cryostat Heater tape with AC cord usually not needed not packed Varivolt AC supply usually not needed not packed Electronics parts box 1 Cryostat disassembly parts box Allen ball L wrench 9 64 Allen ball L wrench 090 Allen ball L wrench 076 ground end Allen ball L wrench 050
62. amp A 334 5 detect variations in the distribution of the flux for this source Lambda Vel Var Var Mu Cep Var Semi regular pulsating star High variability and strong silicate emission make this rather unsuitable as a photometric standard Brelstaff et al 1997 JBAA 107 135 detect two periods 850 amp 4400d from observations spanning 1959 1993 SiO maser is coincident with this star Mu Uma Suspected Var Spectroscopic Binary Sigma Lib Var Variable at optical wavelengths Barnes amp Moffett 1978 IBVS 1518 1 114 MIRAC User s Manual Another possible source of fainter standards is from Hammersley et al 1998 A amp AS 128 207 This list includes stars which are not variable according to the Bright Star Catalog with the exception of Alpha Tau This list without magnitudes or annotation follows HR Bayer Greek letter or Flamsteed HR 1457 Alpha TAU 2077 Delta AUR HR 2335 HR 2443 NU3CMA HR 2459 Psi4 AUR HR 2533 HR 2970 Alpha MON HR 314528 MON HR 3304 Phil CNC HR 373828 HYA HR 3834 HR 3939 HR 4094 Mu HYA HR 4232 Nu HYA HR 4335 PsiUMA HR 4402 Epsilon CRT HR 470170 UMA HR 472866 495441 5315 5340 Alpha 5616 PsiBoo HR 5622 Nu LIB HR 6108 NulCRB HR 615929 HER HR 6705 Gamma DRA denotes standard listed in the Standard Star Tables 5 22 99 A3 MIRAC Filter Data 115 Appendix 3 MIRAC Filters A3 1 Filter
63. and E arrow pointing left and the X and Y flip options are on the output files will also have the X and Y flip applied However if the N direction is down with all other parameters the same then the Y flip would not be applied to put the final image in the proper orientation Then when displaying the image with another software routine such as IRAF N will always be up and E to the left This is not quite true however if the axes of the array are slightly rotated with respect to and Declination The program mrc2fts c is a stand alone program which performs the same FITS conversion functions and can be run on a Sun workstation Appendix 7 provides a description of this program 12 6 DOS Shell This utility allows limited access to DOS commands and small programs There is approximately 400K available to run utilities This is plenty for many commands including COPY DIR CD MKDIR EDIT etc The computer should be returned to the O drive before exiting the DOS shell Typing ret or return from the DOS shell command line will execute both o and exit to return to the o directory and to the MIRAC program 12 7 Unpack Fast Data and Ultrafast Data Files This utility converts files in the fast data and ultra fast data format to image files that the normal DISP Load functions can process The fast data file format has a single header followed by multiple images Each image in the fast data file is in the byte order as it comes dir
64. beams and the pattern noise and the sky plus telescope flux should be effectively subtracted out when the images are subtracted in processing leaving no zero flux pattern noise or gain related pattern However as soon as there is an astronomical object imaged on the array a gain map is required to provide a valid image of the object 78 MIRAC User s Manual If there were no pattern noise and the detector and readout were completely linear then a single image of a uniform background suitably shifted so a pixel value of zero means zero flux and inverted would represent a gain map and could be multiplied times the sky image to flatten it This 15 often done in the near infrared However this is not the case in the mid infrared Also there is no practical source of a single uniform background illuminating the array the same as the sky The telescope which dominates the background will in general illuminate the array differently from the sky So it is necessary to form a gain map for a given spectral filter camera magnification and focal ratio from two flux levels both of which contain the same flux from the telescope The varying part should pass through the telescope in the same manner as flux from the sky Possible sources for this are 1 the sky at one and two airmass 2 the off source beam during observing at what ever range of airmass occurs and 3 the closed dome and the sky with the same telescope orientation The first two method
65. cold stop using the pupil lens also Section A14 8 Select the a suitable wavelength such as 8 8 um with the menu OBS Next Wavelength The wavelength chosen must use filters located in wheels 1 or 3 Put the pupil imaging lens in position 5 22 99 14 Hardware Preparation and Setup 197 using OBS Header Filters 2wheel H pupil imaging Set OBS Next Chopper to Grab The large dynamic range from the cold stop to the hot flux through the pupil from the dome exceeds the dynamic range of the camera A D so the low level must be observed at Low flux range and the high at High flux range With OBS Header Level set at High and a cardboard slipped in front of the camera window set the frame rate to give a reasonable flux level Save a few of these images using OBS Next Save Yes Also save one of them with OBS Save Current Image Save as o pupilhi flt Repeat with OBS Header Level set at Low and the LN2 slide in place Save a few of these images along with one as o pupillo flt Turn on the flat fielding with DISP Load Auto FField using pupilhi flt for examining the high flux and pupillo flt for the cold stop Remove the cardboard in front of the camera window and open the LN2 slide The camera display should show clearly the sharp edge of the cold stop at Low level and the telescope aperture with the secondary mirror as the entrance pupil at High level The dichroic adjustments should be used to center the telescope pupil in the cold stop
66. connected to the test plug and the electronics end of the digital cable connected to the electronics OBS Init Mode Header Next Run PERSE Save Tele DISP UTIL PRN Quit Obs Mode Grab Log Sav OnzOf f Off RA 0 00 Chop gt 4 77 23 34 Off Dec 0 00 FrTimetCms 19 661 EleTenp 25 32 Filtr 1 8 8 pn Burst Mode ON A DT emp 32 59 Filtr 2 207 IntTimets 0 20 DetTenmp 5 277 Wavelth 8 80 RAVUG 2 671 lt 5 gt 4 er tt 10 Section Full Data Max 1653 10 lt 727 33 Dmin 1071 80 lt 13 20 gt Fit 136 54 71 94 3 00 FWHM 0 33 ChiSq 143 321 Total RMS 150 50338 Avg 1286 3231 Num 16384 Background RMS 150 48069 Avg 1286 3007 Num 16383 Source Sum 366 8 Num 1 lt Sky Flux 2858 3 RMS 0 13 DIF 0 1 Limits A D 3619 4 6 gt LinMax 4190 FullW 7508 FrameErrors o Flux MaxMin 3225 2644 BLIP 99 00 Lev Low OutOfRange o gt OBS 8 28 97 15 33 44 c970828a 001 lab IDLE 0 00 0 00 0 1000 DISP 8 28 97 15 33 38 12 Data not saved lab Mode Current Figure A16 1 The MIRAC Main Screen showing Array Test Pattern 5 22 99 16 Checking and Trouble Shooting 207 A16 6 Running with the Array at Room Temperature The camera can be run with the array at room temperature by using the bias switch and bias values given in Appendix 17 A room temperature image is given in Figure A16 2 DISP Init Header Begin
67. crate number and the foam level which should be in place when the item is put into the crate Crate 1 Guider box should be unpacked at the IRTF not at UKIRT Crate 8 Support equipment should not be unpacked except for trouble shooting service and repair Crate 9 Cryogenic transfer tube is not needed on Mauna Kea 22 1999 Page 167 CRATE 1 GUIDER BOX Yellow Fiberglass 18x34x22h 110 Ibs 05 22 99 TV relay optics spacers in envelop 90 inch Guider box in plastic bag TV camera support shelf IRTF Guider box assembly plastic box Allen ball driver handle wrenches 1 4 3 16 5 32 3 32 Allen handle wrench with flat end 5 32 Allen L ball driver wrench 1 4 3 16 5 32 3 32 Open wrench 1 2 for IRTF TV locking nuts Open wrench 7 16 Crescent wrench 100 mm Allen L wrench 3 8 for guider box mounting Guider box mounting screws with washers 6 1 2 12 x 1 5 allen SO TV screws with washers 4 10 32 x 1 and 4 10 32 x 3 4 allen IRTF TV mounting screw with washers spare 1 4 20 x 1 5 Jeweler s loop for eye for pupil focus and adjustment Jeweler s loop for glasses for pupil focus and adjustment TV relay optics pupils SO 067 or 072 IRTF 081 or 088 61 inch to 90 inch bolt circle adapter plate kept at 90 inch telescope 61 inch to IRTF bolt circle adapter plate kept at IRTF MIRAC mechanical interface kept at UKIRT Guider box is not used at UKIRT CRATE 2 CAMERA ELECTRONICS amp CYRO KIT 18x34x22h 100 Ib
68. critical to have this right Otherwise data will be overwritten Note Each data directory is a separate tar file The program will prompt for a response that the entries are typed correctly and for a response for listing the contents of the tape after saving the new directories to the file tarlistb txt or tarlista txt The file name A or B should be chosen corresponding to the tape A or B The program will then proceed to backup the chosen directories It can be left of the day without operator attention Alternative If tape backup is not to be carried out or is complete shut of PC Monitor will shut off with PC without using monitor power switch Initiate Exabyte tape backup on facility computer or transfer of data to home computer if desired Appendix 21 Photocopy log for this day Put away setup and observing log sheets in 3 ring binder Transfer cryogens Appendix 15 NOTE Items in the MIRAC Nightly Startup Tasks list marked with a bar 1 can be carried out at this time in preparation for the next night If backup finishes before leaving shut off PC and monitor power 5 22 99 6 Nightly Startup and Shutdown Check Lists 37 12 Thunderstorm Precautions If a thunderstorm or lightning is likely the following steps should be taken 1 Shut off power to camera and MIRAC computer 2 Unplug the camera power supply power cord and power strip for MIRAC computer If a severe storm is expected 3 Dismount camera from tele
69. depending on the data mode When the header is saved the program reads the current time calculates the airmass value reads the temperatures and heater voltage and updates a number of other parameters At the end of the integration the image is usually displayed to the screen For normal observing when the integration time in each beam is several seconds these operations add no extra overhead because they take place while the camera is integrating However for very short integrations such as those intended to freeze the seeing motion or chopper jitter the header file and display operations can cause a significant reduction in duty cycle The fast data mode was designed to increase the efficiency of the data taking process in this special case of very short integration times This mode is selected by selecting Fast Data in OBS Mode and setting the How many Obs Run to the desired number of images per fast data file The difference in this mode is that the data is saved in a file with a single header followed by many images The data is saved directly from the array processor board without sorting to save time and only the last image of the set is displayed to the screen This greatly reduces the overhead time for saving each image The data files saved in this manner are called packed files and are designated by a first letter of P instead of C as in the normal MIRAC data file naming convention Section 9 3 Each image set Grab or Chop
70. detector The MIRAC3 cryostat is shown in Figure 2 2 Reflective optics in the camera cryostat provide achromatic diffraction limited imaging at a nominal scale on IRTF of 32 arcsec pixel A 2D at 9 4 at a camera magnification of 43 with additional zoom capability from magnification 43 to 1 14 The camera cryostat contains three cold filter wheels with a 16 bandwidth filters at 2 2 3 8 and 4 8 um a 4 bandwidth filter at 7 9 um 10 bandwidth filters at 8 8 9 8 10 3 11 7 and 12 5 um 2 6 bandwidth filters at 17 4 and 17 8 um 10 bandwidth filter at 18 0 um 7 bandwidth filter at 20 6 um an N band filter 8 1 13 1 um and a CVF with 1 8 resolution from 7 7 to 14 5 um A pupil slide provides for focal ratios of 1 15 4 16 1 32 1 36 and f 45 for the MMT SOFIA CTIO 4 meter IRTF UKIRT and Steward Observatory 2 3 meter telescopes Digital and analog electronics mounted at the cryostat provide for single and double read with a minimum pixel sample time of 1 07 usec and a minimum full array read time of 1 09 msec The array can be read out in continuous or burst mode with frame time on chip integration time up to 256 read times Hard wired arithmetic units provide for fast coadding of up to 4095 frames before sending the images via an optical fiber to a digital array processor DSP in a Pentium PC A sub portion of the array in units of 1 4x1 4 of the full array can be chosen for coadding and transmitting to the PC Full array
71. dichroic adjustment collimation of the camera with the telescope The first and most direct method is to use the MIRAC3 pupil imaging lens and to align the image of the telescope secondary mirror to the image of the camera cold stop The second method is to utilize the contrast between the cold sky around the secondary mirror and the warm mirror cover or dome as viewed by the secondary Both methods require the camera to be running Section 5 2 and can be carried out during daylight or at night The dome must be open for the second method An open dome will yield greater contrast with the first method The dichroic is a 45 degree IR reflecting mirror in the guider box It is adjusted with two multi turn dials are on each side of the guider box These are marked Dichroic RA and Dichroic Dec based on the assumption that the camera is camera is aligned with the window either North or South The adjustments each tilt the mirror 0047 radians turn Hence in the North South declination direction the beam will move 0094 radians turn and an 1 45 beam 022 rad will move its diameter with 2 4 turns In the East West R A direction the beam will move 0094 x sin z 4 0066 radians turn and an f 45 beam will move its diameter 3 3 turns A14 11 1 Dichroic Alignment using Pupil Imaging Lens The pupil should be properly set as described in Section A14 8 The magnification should be set to the 0 8 position to put the detector at the focus of the
72. editor from the DOS shell edit filename enter When a macro encounters an unusual or unexpected condition a warning message appears and the macro terminates execution For example if the macro is about to overwrite a pre existing file a warning message will appear on the screen and control will return to the keyboard to choose whether to overwrite the file The macro will not resume operation Also macros may be terminated when executing by pressing the Alt F1 key Current assigned macros are Fl Print Execute Print and return to Obs command line The printer Postscript file or postscript printer is set in PRN Init Printers F2 SaveFits Save currently displayed image in Fits format to data and backup directories The first letter of the file name is F instead of C Findstar For finding an object or focusing Mode chop Int 0 5 sec How many 100 Save off Read offsets off Command off Zero current position Run F4 Stdparm For standard star observation Mode chop nod Int 5 sec How many 2 Read offsets off Command off Save off Zero current position Ends at Source name for updating If required command file must be turned on in Obs Next menu Start observation with F10 Savrdrun 5 22 99 7 Observing Procedures and Check Lists 43 F5 Objparm For observing program object Mode chop nod Int 12 sec How many 2 Offsets off Command off Save off Zero the offsets Ends at Source name for updati
73. files to the disk in the current directory automatically creating subdirectories if the original data saved were in subdirectories tar tvf dev rstl list the files on a tar tape 5 22 99 21 Tape Backup 237 mt f dev rstl rewind rewinds the tape for unloading if automatic rewind has not been used allocate d stl frees up the drive for the next user To unload the tape press the button and wait about 30 seconds for the door to open Remove tape and close the door Saving multiple files on a tar tape is possible but not for the faint of heart There is no end of tape marker or any protection against overwriting an existing tar file One must manually space to the end of the tape to begin the next tar file For example if one file has been written and no rewind has been performed the next tar cvf can be issued to write the next file If at the beginning of the tape one issues the command mt f dev nrst1 fsf 1 to space forward 1 file Replace the last 1 in the command to space forward any number of files Then the next tar command can be issued Using tar tvf to space forward while showing the tape contents can also be done but this command does not actually go to the next file The tar command processes the file to the end but does not go beyond the End of File EOF marker at the end of the tar file One must still execute the mt f dev nrstl fsf 1 command to space to the file However this command must simply move over
74. flux levels by using the same camera settings Also since residual pixel levels after resetting once will be dependent on flux level it is best if the camera has the capability of multiple resetting at the start of each frame The gain map which is multiplied times the image is formed from the reciprocal of the difference of the images at the two flux levels normalized to a mean of unity It goes without saying that the astronomical images must also be obtained within the linear range of the array or all this is for naught 5 22 99 11 Reading Stored Data and Data Processing 79 11 Reading Stored Data and Data Processing The two basic steps to see stored data is first to load it in and secondly to display it using the desired display option The method of reading in data will depend on whether the image is a processed map or raw data and if multiple files are to be combined in some way to generate an image to be saved and displayed All data that is read in is stored in the program s map display buffer From that point it can be displayed and saved to a file in the map format or if it is raw data saved to a raw data format file The difference is that the raw data is in 4 byte integer format and stores each separate frame off source chops and nods before and after reset samples if in Dble2Samp mode whereas the map files are in a 4 byte real format and store one number per pixel the result of all the off source subtraction and sam
75. for fiber optics cables Couplers for fiber optics 4 AC ground isolation adapter plug Tweezers 2 Paper clips BNC T s and barrels RS232 transerv transceiver UKIRT Centre Com Network transceiver 9 volt battery Camera setup plastic box Allen L wrench 3 16 Allen L wrench with flat end 3 32 Allen handle ball driver 3 32 Allen wrench set Screwdriver 1 8 for cable strain relief screws and pupil adjustment Jeweler s screwdriver 1 8 inch Plastic jar with electronics box cover plate screws Spare cryostat mounting screws 2 socket head machined 5 22 99 13 Shipping Procedures Shipping Inventory 171 End covers for fiber optics cables Tweezers Spare optical fiber cables CRATE 6 MONITOR Yellow Fiberglass 18x34x22h 99 Ibs 05 22 99 Computer monitor in plastic bag swivel base removed Notebooks and folders 4 inches Log sheets 3 ring binder Current log 3 ring binders with dividers No 1 and No 2 MIRAC Design 3 ring binder Current results 3 ring binder MIRAC Users Manual here or in travel kit Current logistics folder here or in travel kit Current observing proposals folder here or in travel kit Airmass lists here or in travel kit Object lists here or in travel kit Computer items plastic box Disk cleaning kit 3 1 2 D connector RS232 25 pin gender changer D connector RS232 25 pin cable matcher Ribbon cable 25 pin RS 232 20 feet spare Telescope command RS232 cable 15 feet for S O and UKIRT RS232 standard
76. min 3 sec for on source off source nod can be 1 sec if object only in one nod beam H eader O bs Parameters N od and chop parameters Turn on the Chopping Secondary Mirror Control Panel Power 8 3 Observing with MIRAC 8 3 1 Acquire standard star eg alpha Boo Set Next parameters these are set for every run Wavelength 8 8 microns Frame time 8 msec The following parameters are set automatically by the function key F3 Number of observations 100 56 MIRAC User s Manual Short integration time eg 5 sec Just Chop no Nod Dont save No offset file No command file Offset systematically until object found eg 30 arcsec S 30 arcsec N 30 arcsec E 30 arcsec W Field of view about 45 arcsec Check sky flux should be close to the upper end of the linear range shown on the screen with no pixels out of range 8 3 2 Focus on standard star Set Next parameters as above this can be done with F3 Short integration time Chop Nod Dont save Record FWHM values for each focus setting choosing lowest FWHM values for focus 8 3 3 Take images of standard star 8 3 4 Acquire object of interest etc etc 8 4 Shutting Down MIRAC 8 4 1 Make sure you are not taking data W ait E nd 8 4 2 Power down Turn off Chopping Secondary Mirror Control Panel Power Camera Electronics Power OFF right switch on Power supply Temperature Monitor Power OFF left switch on Power supply 8 4 3 Quit Mirac Q uit Yes 8 4 4 Log file Copy the log fi
77. of decimal places type scale 2 number dd to delete the entire line the cursor is on dw to delete the word or portion of word under and after the cursor h to move left or west one character i to insert text under the cursor enters insert mode 1 to move down or south one line k to move up or north one line 1 to move right or east one character to insert text a new blank line after the current line enters insert mode O to insert text on a new blank line before the current line enters insert mode 5 to substitute a character with a string enters insert mode x to delete the character under the cursor iq to quit vi 4 to quit vi without writing changes to save or write a file 5 Formatting Files Construct source file to run through nroff formatter including any of the following commands to left justify a paragraph tocreatean itemized paragraph like this one to center text on the page ul to underline portions of text 5 create a blank linespace force the end of a line a linebreak 230 MIRAC User s Manual To format the source file type nroff ms source filename You will probably want to redirect the output of nroff into a destination filename so you can print it out afterward 6 Search Files Type grep search string filename to type out lines containing the string in a specific file grep search string filename s to
78. of the pupil to center it on the secondary image Tighten the clamping plate screws Step 3 Using a jeweler s loop to view the pupil and the image of the secondary created by the TV relay optics adjust the position of the pupil mounting plate to provide simultaneous sharp images of the secondary and the hole in the mounting plate A good check for this is the absence of parallax motion between the pupil and the secondary image The adjustment requires a 5 32 allen wrench to loosen the small screw on the underside of the relay optics assembly 196 MIRAC User s Manual Step 4 Reexamine the pupil and secondary image with the loop to confirm that the pupil is well aligned Repeat Step 2 if necessary Check with the relay optics mirror in both the high and low magnification positions The high mag and low mag dials can be used to fine tune the pupil alignment with the secondary in the vertical direction only Step 5 Mount the TV camera A14 10 Telescope Balance Balancing of the telescope is carried out by the operator All MIRAC equipment cables and cryostat and the facility TV should be mounted first The balancing requires slewing to dec and hour angle extremes and can result in some loss of cryogen At the IRTF and UKIRT the balance will depend on what other instruments are mounted on the telescope Previous balance weight settings should be in the telescope operators log A14 11 Dichroic Alignment There are two basic methods for the
79. ol 9 Check Observing Parameters Obs Header Observing Parameters Chop frequency 1 10 Hz Nod and Chop Parameters Nod wait 2 sec 5 sec for UKIRT 20 60 guided nod 6 5 sec for larger UKIRT nod 4 0 sec for UKIRT 5 22 99 6 Nightly Startup and Shutdown Check Lists 33 unguided nod Check UKIRT telescope control parameters Section 5 2 Start of Run setup Item 15 Off src nod wait 2 same as nod wait when object is in both nod beams Wait time for chop 6 6 msec minimum of 2 reads lt esc gt NOTE There is a minimum chop wait reads which is set to 1 when the program loads and can be changed in OBS Init Program Values Min Chop Wait Cycles Ol 10 Check display settings NOTE The macro F6 Dispparm can be used to make all the display settings Disp load Mode Current Data format MIRAC Load Auto Mask on Gain off Ffield off Default mask e g bad1126 msk e 11 Save the current parameter settings Obs Init Mirac Settings File Save Header Current hdr enter yes esc This should be repeated occasionally during the night to assure that current hdr contains up to data parameter settings e 12 Power up the camera The MIRAC program should be running and MIRAC power supply temperature monitor switch should be on Confirm that the detector temperature is below 10 K It should be 3 9 K at the summit of Mauna 4 3 at sea level Do not turn on camera power if detector is not properly cold
80. read in before doing any math operation The following operations between files are supported addition subtraction multiplication and division Also the same operations can be used with scalars and images in combination The operation is performed using temporary image buffers and then the result is stored in the main map display buffer Parenthesis are allowed to specify order of operation 5 22 99 11 Reading Stored Data and Data Processing 81 The following are some examples of operations that can be performed between raw data images 1 Add three images number 5 6 and 13 5 13 2 Multiply image 5 by 17 and subtract image 11 divided by image 3 17 5 11 3 3 Multiply the difference between images 7 9 by image 15 a7 a9 al5 11 1 5 Mosaic This mode generates a mosaic of individual observations taking into account the offsets between the observations There are two decisions that must be made before running the mosaic mode First is the choice of offsets used and the second is the source of the files to read in The offsets can come from one of four sources the offsets stored in the data file header calculated from the data in the observation file read from a text list file that was previously constructed by the user or typed in from the keyboard as the images are being combined The calculated offsets can either be based on the peak value in the map or the centroid of the region
81. set for the calculation The result of the calculation is stored in the default display image overwriting any current image being displayed 12 12 Display Image Arithmetic This allows certain math operations to be performed on the data that are currently in the image display buffer Only the data in the buffer is altered the image must be explicitly saved if the image on the disk is to be affected The following operations are supported Add Subtract constant a real value can be added or subtracted from each pixel in the image Multiply Divide by constant each pixel in the image can be multiplied or divided by a real scalar value Invert map each point on the map p i j is set equal to a new value P 1 j where P 1j 1 0 p i j Justify map the data in the array are shifted so that the starting coordinate of valid data 15 at the origin 1 1 Boxcar Smooth map the image is smoothed using a smoothing window of adjustable size Every point on the new map is the average of all the pixels on the old map enclosed in a box the size of the smoothing window centered on that pixel For smoothing windows whose size in pixels is an even number the resultant map will be shifted by one half pixel towards the origin 98 MIRAC User s Manual X Y flip the image is flipped in X or Y Two successive flips will unflip the image Performing an X and Y flip is equivalent to a 180 degree rotation If the user wants a map to appear in the
82. should not be a big problem 5 22 99 5 AIRMASS Program 123 Appendix 5 AIRMASS Program The program AIRMASS EXE and its C source code AIRMASS C are in the C MIRAC directory on the MIRAC PC The compiled C program can also be obtained from the MIRAC home page on the WWW Section 2 1 This program produces a listing of the airmass of objects to use as a guide to observing The input to this program is a source file with the same format as used by MIRAC and by the Steward Observatory telescope control system ALL CAT YSO CAT etc The output is a text file e g PNAMS TXT MIRAC directory contains the WordPerfect file AIRMASS WPW to format this text file for a post script printer If the TYPE field has been used to designate the type of object then selection of the objects to display airmasses for is possible For example it is often convenient to have a list of standard stars and a separate list for objects Usually the airmass of the SAO reference stars are never required since they are so close to the object airmass The following types have been defined STD Standard Star QSO Quasi Stellar Object SAO SAO catalog star HII HII Region PN Planetary nebula DSH Dust shell around star PPN ProtoPlanetary nebula AGN Active galaxy nucleus SFR Star forming region YSO Young stellar object GAL Galaxy SBG StarBurst Galaxy MCD Molecular Cloud Currently only the STD and SAO types are recogni
83. shown for the background defined as all pixels not in the source If DISP Init Stat Fit is set to none then the source is taken to be all points some factor above the noise sigma which is determined iteratively from the points not in the source The sky flux is the mean of the array for the off source beam offset so that a zero value corresponds to zero flux regardless of the flux level set in OBS Header Observe Fluxlevel The nominal offsets set in OBS Header Hardware Offset Values are 1572 3368 and 6058 for the three levels low medium and high full well flux nominally 7508 and the parameters for the sky linear max are also set in this menu The SKY RMS value is the standard deviation of the current and previous five flux measurements The SKY DIF is the difference between the last two This line provides a monitor of the sky and telescope brightness and their variation quickly indicating presence of cirrus clouds or increase in water vapor in the atmosphere Under good conditions the sky flux should not vary by more than a fraction of a unit between consecutive images The flux limits are the A D limits shifted by the offsets described above The flux maxmin are the extreme values of the flux which should be within the flux limits The sky flux should be less than the linear max which depends on the frame time a high dark taken to be that for the 10th highest dark current pixel and the signal level at which the array start
84. sided for multiple records of the run or scanned into a computer for a digital facsimile record Individual nights can be photocopied separately for different observing projects CRYOSTAT The cryostat sheets should be the first pages of the log for a run numbered 1a 1b Use the cryostat sheet to record cryostat disassembly and maintenance cryostat vacuum pumping cryostat cryogen levels expected hours until empty and fills and LHe supply dewar level WORKSHEET Use the worksheet for trouble shooting recording camera bias voltages and preamp SETUP OBSERVING offsets and calculating sensitivities and telescope emissivity This can also be used for notes taken when adjusting the dichroic focusing and measuring the pixel scale although these can also be recorded on observing sheets Use a setup sheet at the beginning of each observing night Complete Accomplishments and Problems at the end of the night Day is the sequential day of the run starting with 1 It can show the first and last day of the run The local date is useful since the telescope observing schedules are in local time and the daytime activities are usually in local time Giving the local date explicitly reduces the chance of confusion between UT data and local date Many of the items such as directory and file names display flips and orientation IR magnification and chop and nod parameters are reminders to enter these items in the MIRAC program header
85. such as the bias rates wobble vectors offsets etc can be typed in from the MIRAC computer Commands can also be issued such as Move to next and turning the tracking on and off Information on the function and use of these commands for the S O 2 3 m telescope can be found in the manual by Comsoft PC TCS version 3 5 dcs Users Manual October 1992 Information on the UKIRT version can be found on the WWW site The most important capability of the control system however is the offset commands that MIRAC can send directly to the telescope computer This allows the user to enter the offsets to be used to obtain the images that can later be combined to form the mosaiced image The offset information is stored to the header of each observation file as well as written to the observing log file To actively control the telescope offsetting with the MIRAC program the Control Telescope offsets flag must be turned on in the OBS Telesc Telescope Control submenu If this flag is off then the offsets entered are stored in the observation file headers but no commands are sent to the telescope the Observer would have to move the telescope by hand 9 10 3 Ethernet Control of the Telescope At the IRTF the telescope can be sent commands via Ethernet Two external DOS programs are used BEAM EXE and OFFSET EXE These programs are run automatically by MIRAC to establish connection with the IRTF TCS and to pass the necessary parameters such as the nod be
86. taken over no more than one hour are bracketed by observations of the standard before and after for the same filter This also gives an indication of any drift in the calibration Depending on the sky conditions one may have to switch more often between source and standard to remove effects of a rapidly changing sky It is also preferable that the standard star be at a similar elevation to minimize the effects of airmass correction To derive the airmass correction a standard star should be observed at several different airmasses throughout the night at each wavelength of interest Assuming that the sky is relatively stable this will give an indication of the transmission of the atmosphere as a function of airmass An alternate method is to observe two separate standards one at a low and one at higher airmass This method however is dependent on accurate previously measured fluxes from both standards If the standard star observations are to be also used as a measurement of the instrumental point spread function PSF then some attention should be given to making the star observations in a similar way as the source observations with a number of offsets Otherwise the PSF of the star will not be an accurate estimate of the PSF on the source There are a number of factors which affect this integration time per observation number of observations source flux distribution and brightness telescope drift offset errors method of aligning the image
87. temp too high the cryogens have run out need to refill 8 2 5 Set up data directories in MIRAC Note type space to edit an existing directory path lt backspace gt to delete the existing path and type in a new one O bs I nit D ata file directory d dY YMMDD cr your main data directory path B ackup data directory jd YYMMDD cr backup data directory path esc 8 2 6 Check your source enter catalog file and source name H eader 5 ource Parameters L ist of sources enter catalog file name S ource Name enter source name F ind source in list will update the info for your source esc After catalog file is entered the source name can be entered in the O bs Next menu and it will automatically search the source file for the coordinates 5 22 99 8 Short Form Instructions 55 8 2 7 Turn on the camera Turn on the camera switch right switch on the MIRAC power supply Wait until the fan comes on the red light will come on Check that the data I O light on the PC comes on 8 2 8 Initialize the camera I nit I O Y es C amera Y es esc 8 2 9 Initialize the filters N ext W avelength P Home all filters Y es takes half a minute the camera must be on 8 2 10 Set up Chop and Nod The telescope operator sets up Chop throw eg 60 arcsec N S Nod throw eg 60 arcsec E W Set chop frequency in MIRAC H eader O bs Parameters C hop frequency Set Nod and chop parameters set wait times for nods
88. test pins The nominal bias voltages and cable pinout are given in Table 17 1 The biases can be adjusted by removing the cover of the bias box 206 MIRAC User s Manual The clocks can be checked by running the camera without the cryostat Section A16 5 and using an oscilloscope to probe the digital cable connector Table A17 1 A16 5 Running the Camera without the Cryostat The camera can be run without the cryostat for testing the electronics and computer operation For this test the camera electronics signal cable which normally goes to the cryostat must be connected to the test signal connector at the top of the electronics unit This is the way that the camera is normally shipped The top cover plate must be slid back to access this The digital cable should be connected at the camera electronics end but not at the cryostat end The test pattern is shown in Figure A16 1 The test signal runs with a 4 step pixel cycle low low high low with a superposed two step 128 pixel cycle with the first 64 high and the next 64 low The center and spread are adjustable with the edge pots on the controller circuit board With Obs Header Hardware Reorder off the pattern will appear as described with 32 sets of horizontal bands starting with the second pixel in the cycle because of the AD sample timing delay With reorder on there will be 4 sets of bands WARNING Do not run the camera electronics without the signal input cable
89. test probes with hook grip ends 2 Ball clip leads 2 missing Coax test cables with miniature female connector and BNC 2 Coax test cables with miniature male connector Twisted pair signal processor test leads with connector 3 Allegator clips BNC adapters and T s Candle and book matches Short 50 pin ribbon cables for Foxy board in computer 2 A D 2 spare Qtips Monitor AC cord Spare instrument AC cord BNC cable 12 feet Ribbon cable 25 pin 20 feet printer not normally used Foxy termination board with connectors Spare cryostat window Small plastic box Spare camera electronics signal processor card Camera electronics extender card PC extender card Bias monitor card Box of spare dichroics Component data sheets 3 ring binder CONTINUED CRATE 8 SUPPORT EQUIPMENT CONTINUED 4 of 4 File box with working drawings folders Analog Digital I O box Bias amplifiers Cables and backplane Computer Controller Cryostat and optics Cryostat assembly Data Command link Detector and Dewar Wiring Detector Information Filters Filter Motor Controller Guider box Labels Preamp Power supply Signal Processor Spare Parts Temperature Controller Timing Circuit board foam pad CRATE 9 CRYOSTAT TRANSFER TUBE Carton 21x8x75h xxx lbs 05 22 99 MIRAC LHe transfer tube 90 INCH ONLY 05 22 99 LHe transfer line LHe storage dewar level sensor Oscilloscope with test probes and long BNC cable Infrared catalog two volumes Gezari and Mead
90. testing The departure time provides for a morning s sleep an afternoon for packing and a night s sleep 5 22 99 3 Observing Run Arrangements 15 IRTF Observatory Arrangements The basic arrangements are specified in an IRTF form which must be filled out six weeks prior to the run This includes observers observers to be subsidized for lodging and meals 2 arrival and departure schedule and instrument and cryogen requirements The usual cryogen requirements for two days of preparation and four nights on the telescope are 32 liters of LN 12 liters for cooldown plus 4 liters day for 5 days and 42 liters of LHe 12 liters for cooldown and 6 liters day for 5 days including transfer loss and liter day boil off Special requirements include our bolt circle interface plate in storage at the IRTF use of gaseous nitrogen the first day at the observatory to remove the precooling LN from the LHe reservoir a table along the computer room wall for setting up a quiet power strip a thin Ethernet connection with transceiver to thick cable a telescope control paddle intercom microphone two monitors for the telescope status and guiding video and BNC cable from the telescope chopper external reference input interface box This information is given in the IRTF requirements list in Section 3 3 The form can be found on the IRTF home page http irtf ifa hawaii edu Direct email contact may be made with IRTF director Bob Joseph in the Ho
91. the EOF marker so is executed almost instantly A21 3 2 Steward Observatory Tar Macros At the Steward Observatory 2 3 m telescope are three macros tarwrite tarread tarlist and deallocate which take care of the various opaque command line parameters required The tar macros are also in the MIRAC directory of the camera PC and can be transferred to the unix computer if desired The following commands use the macros The name of the tape drive mtc mtf etc should be marked on the unit allocate mtc to allocate the tape drive deallocate mtc to deallocate the tape drive at the end of backing up The drive can be allocated before or after loading the tape To load a tape push the black button on the front of the drive to open the drive door In about 30 seconds the door will open Insert the tape close the door and wait about 30 seconds for the green light to come on tarwrite writes entire current directory and subdirectories to a tar file on the tape overwriting any previous information on the tape The macro then reads back the contents of the tape printing the file names on the screen and in a log file named tar log located in the current directory tarlist reads contents of tape and creates the log file tar log 238 MIRAC User s Manual tarread reads the contents of the tape back to the current directory on disk overwriting any pre existing files with the same names 5 22 99 A22 Weather and Tau Information 239 Appendix 22
92. the file aml 9 the list to the file am2 10 Edit the file to contain only those file names which are 11 7 um grab observations at 1 00 airmass 11 Edit the file am2 to contain only those file names which are 11 7 um grab observations at 2 airmass actually 1 5 airmass in this case 12 Construct an average of the 1 airmass grabs store it in aml 117 13 Construct an average of the 2 airmass grabs store it in am2 117 14 Subtract the 1 AM image from the 2 AM image store the result in gainll7 15 Do statistics on the image to find out the average mean value 16 Look at the image make sure it looks reasonable 17 Divide the gain map by the average value This normalizes the image so the average value is 1 0 to change the data values as little as possible from their original counts values 18 Invert the gain map so that it can be used as a multiplicative map by the programs that need it 19 Do statistics to make sure average is now 1 and check standard deviation 20 21 22 23 24 25 26 Dykes 28 29 30 3L 32 33 34 35 36 5 22 99 Some points below zero eliminate pixels that are much larger than 1 non responsive and negative pixels complet Divide gain map by 0 5 truncated to the nearest integer to a value of zero If there were negative values One can do the following decide what the minimum be say 0 5 then for example take it
93. the mirror aberrations as well as miscollimation But it is a useful check 3 In focus star image Run as in part 2 but with the telescope in focus Monitor the FWHM and try to adjust the collimation to minimize the FWHM and optimize the image appearance Since the image is affected by telescope aberration and seeing as well as collimation this is the least sensitive unambiguous and satisfactory method 4 Using pupil imaging lens The illumination of the telescope aperture by a star and centering of the secondary in the aperture can be observed with the pupil imaging lens Section 14 11 1 A14 14 Setting the Telescope Nod Parameters Step 1 At the Steward Observatory telescopes make sure connection has been made from the RS 232 port COM 1 on the MIRAC PC to the telescope computer connector in the control room At the SO 2 3 m telescope the connector is on a panel on the wall near the observer s monitors At the 1 5 m telescope there is a cable that runs from the back of the telescope control console The special MIRAC telescope communication cable must be used to allow the PC to interface properly Make sure the MIRAC program telescope COM port is set to COMI in the menu OBS Telesc Telescope Control Proper connection can be tested quickly by trying to send command such as setting the paddle guide rate to a certain value The OBS Telesc Telescope control Offset control Command Tel offsets flag must be turned on Step 2 Set the nod
94. three combined are typically 5 arcsec 2 The sensitivity is for signal to noise 1 1 sigma in one minute elapsed time including chop nod and offset waits with the source in one of the chop nod beams The noise observed is produced by shot noise from the telescope and sky background detector read and system A D toggle noise detector low frequency excess noise and sky noise Typically the total is 1 04 to 1 1 times shot only noise 3 For a small source the chop and nod throws can be set to put the source on the array in all beams This gives an increase in sensitivity when these images are combined of a factor of 1 414 for chop only and 2 for chop nod 4 Images can be co added for an hour or more of observing with the noise decreasing as the square root of the time However if the source cannot be detected in a one to four minute observation the telescope must have autoguiding to provide satisfactory registration of the co added images 5 The sensitivities were determined using Gamma Aql Beta Gem and Beta Peg at the IRTF on January 28 1997 At that time water vapor in the atmosphere was high resulting in poor sensitivity at 7 9 17 4 17 8 18 0 and 20 6 um The 18 0 sensitivity is consistent with 40 transmission and corresponding 6 emissivity 6 For the UKIRT 3 8 m telescope the pixel size is 27 arcsec The diffraction FWHM is smaller by a factor of 1 26 than for the IRTF the surface brightness sensitivity greater b
95. to be 1 2 imarith 117 1 2 temp Then set to zero all pixels that were zero by doing 10 Reduction of MIRAC Data using IRAF these are bad pixels store as type short all bad pixels find what the lowest value of Construct a temporary map by imarith temp 1 7 temp pixtype short imarith temp temp temp 1 7 Th 122 0 5 imarith mask temp mask Divide mask by itself are Wri Wri Convert Alpha and Do Read the FITS Make a fil Loo name making Convert the the fits files have a f as the iraf images have Do the cross correlation the reference and window images the few doing the peak eval near 1 in all cases successful makelist to convert the cross corre Run the fil Type the cross correla zero and therefore una mask images we just made the airmass correction pk200 the final image n remov to convert all Ffected te mask file to FITS file for use by programs te gain file to FITS file for use by programs Tau images to FITS le containing the list of files to p k at the files just read in the peak and hit the spacebar Make a note of any bad files near zero Several steps may be required to the process of eliminating pixels and renormalizing the gain which forces numbers to be This causes all values 0 5 to be put values gt 0 5 are some positive integer
96. to temporarily stop reading the command lines from the file The program will continue with the current observations then stop when it is done Execution of the command file can be restarted with OBS Wait Resume command file can be terminated by using OBS Wait End or OBS Wait Abort Use of the LOADHEAD and the EM commands will allow the observer to do a wide variety of tasks in a command file For setting the camera parameters the user would prepare a number of different header files with all the desired values entered Then a LOADHEAD and INITCAM will set up the system exactly as requested Using the EM command the user can have the program do any desired action that doesnt require interactive input Note that all macros should be defined to start at the OBS command line menu 5 22 99 7 Observing Procedures and Check Lists 45 The command file mode is set up in the OBS Mode menu First the file name is entered in The command file name The full path should be given if the file is not in the default directory Then the selection Use command file for Run should be turned on Then the OBS Run command will begin the command file execution The command files can be listed from the DOS prompt with dir cmd enter and viewed with type filename enter edit filename enter A number of macros have been created to assist with command files These include frame time macros such as frame33 and integration time macros
97. to use this Our back focus is similar to NSFCAM On axis Camera Not required Cryogen transfers Only one a day will be required for MIRAC3 We would like to have IRTF operators carry them out at the end of each observing night with some new instruction for MIRAC3 from us Shipping back to Tucson MIRAC will be packed by Aditya Dayal John Spencer and Glenn Orton Nov 23 24 Thu am immediately at the end of observing We would like it to be taken to FedEx the next day or so We will provide shipping papers 3 4 Cryogenics Cost At the University of Arizona in Tucson liquid nitrogen costs 0 50 liter and liquid helium 5 50 liter as delivered in the storage dewar At the Steward Observatory telescopes there is no charge for liquid nitrogen Liquid helium must be purchased by the observer At the IRTF there is no charge for liquid nitrogen Liquid helium is charged at the rate of 18 30 liter for the helium consumed during transfers including transfer loss There is no charge for daily boil off loss dewar transportation loss or unused liquid helium At UKIRT and the MMT there is no charge for either liquid nitrogen or liquid helium 18 MIRAC User s Manual 5 22 99 4 Software Preparation 19 4 Software Preparation The following highlight some of the more important steps to take before beginning the first night of the observing run Some of these tasks should not take long so they could be done on the mountain after set
98. vector in the telescope control computer to the desired value This can be done using the MIRAC program or the telescope control computer For an extended source the nod should be 30 to 60 arcsec to the north or south For a compact source is can be set to slightly less than half the field size to put both nod positions on the array Be sure to set the R A nod value to zero if only nodding in Dec Step 3 Center the source on the array position and define the current position to be BEAM 1 in the telescope control computer Again the telescope operator can do this function from the telescope console Step 4 Take a test integration in the NOD mode to see if the link is working properly Watch the image motion as the nod is performed and evaluate how long it takes for the image to settle 5 22 99 14 Hardware Preparation and Setup 201 This time should be the entered as the nod wait time in the OBS Header Observing Parameters menu On the Steward telescopes 2 to 4 seconds is a reasonable value Step 5 If the MIRAC program control of offsets is desired then turn on this flag in the OBS Telesc Telescope Control menu Make sure the proper site and telescope are selected in the OBS Header Site and Telescope menu and that the plate scale and camera magnification are set to the proper value the plate scale values are automatically entered for the SO 1 5 and 2 3 m and the IRTF Also it is useful to have the Ask for offsets flag set whic
99. 0 285 231 210 2411 1037 909 718 664 2346 876 892 751 689 595 231 188 160 145 552 215 176 145 131 552 172 295 114 926 765 69 5 3616 2013 1716 1432 1362 459 191 155 134 121 443 156 158 608 495 402 365 158 49 5 7282 4830 3930 4404 4386 5731 3499 2847 2534 2302 2081 920 770 637 584 2024 749 763 673 622 828 384 312 265 246 813 301 306 270 252 443 187 152 120 109 431 151 154 126 115 1197 581 473 405 368 1197 439 468 402 375 523 242 197 198 178 573 258 218 192 175 279 116 943 824 748 97 84 78 2620 1096 1092 895 821 477 201 164 151 139 9083 46124 37534 44042 40002 431 133 10 8 816 7 35 1092 731 1034 1923 1915 301 135 117 964 883 573 265 216 175 159 10 6 117 125 135 174 178 18 20 6 284 261 235 155 149 145 1141 571 507 440 277 265 260 199 163 143 123 743 711 695 533 545 488 420 246 235 230 177 620 521 540 475 108 102 878 436 417 408 313 102 864 717 473 453 443 340 119 98 3 540 488 420 246 235 230 17 1238 1150 1126 678 648 634 486 90 5 905 779 514 448 43 9 2337 115 98 3 284 249 215 129 124 121 9 3 344 28 4 4493 3951 3401 2577 2465 2411 1849 2151 1891 1785 1074 1027 1005 771 471 421 363 220 21 206 158 555 479 502 441 211 186 148 804 855 836 64 1 227 198 205 182 872 746 642 394 376 368 283 106 87 2 90 5 80 3 286 252 235 142 135 132 102 326 281 207 261 131 108 928 743 711 695 533 142 130 112 678 648 634 48 6 592 521 457 275 263 257 197 61 54 674 598 515 310 296 290 22 113 992 1027 618 591 578 444 31087 39510 340
100. 0 70 00 lObservatory C Wlth 8 500 70 00 Telescope RAAR Plate Scale mm Ps 9 000 ca Site Latitude E Wlth 9 500 70 00 Longitude of site Wlth 10 000 70 00 L G Wlth 10 500 70 00 H Wlth 11 000 70 00 I Wlth 11 500 70 00 J With 12 000 70 00 Wlth 12 500 70 00 L Wlth 13 000 70 00 Wlth 13 500 70 00 N Wlth 14 000 70 00 Wlth 0 000 0 00 P Wlth 0 000 0 00 Sites A Kitt Peak Catalina C Mauna Kea D Cerro Tololo e Mt Hopkins F Other Site Other Telescopes SO 2 3m SO 1 5 m 4 m UKIRT MMT Other F Data Files Data File dir d d941229 Backup Data Dir i Nd941229 Gain Matrix Flat Field Mask file o bad1106 msk_ 149 150 MIRAC User s Manual A12 1 4 OBS Next Observation 2 2 2 2 Object Name ALPHA BOO Wavelength 8 800 Integration time 5 086 Frame Time ms 17 4763 Chop Nod Mode Chop Nod Save all observations Off How many Obs per run 2 Read offset file Off Use command file Off Link Frame Filter Off Macros gt DOS Shell Zero current position Filter Selection 4 A 2 2K 16 W2 3 81 16 2 4 8 16 2 D 7 9Me 4 W1 E 8 8 10 1 259 98 10 1 10 3 10 1 10 6N 8 1 13 1 pm W1 7 21 0 W1 J 12 5 120 W1 17 400 2 6 12 L 17 801 2 6 2 18 0Qshort 10 W2 20
101. 000000000e 01 ARRAY LOCATION OF REF PIXEL CTYPEl OF COORD ON AXIS 1 CTYPE2 DEC TAN OF COORD ON AXIS 2 HISTORY THIS FILE WAS CONVERTED FROM MIRAC PC FORMAT BY MRC2FTS V 2 31 HISTORY OF CONVERSION Fri Nov 20 08 57 12 1998 HISTORY ALL OFF SOURCE FRAMES IN THE ORIGINAL IMAGE HAVE BEEN SUBTRACTED HISTORY HE IMAGE HAS BEEN ORIENTED WITH NORTH UP AND EAST TO THE LEE END 5 22 99 10 Reduction of MIRAC Data using IRAF 137 Appendix 10 Reduction of MIRAC Data using IRAF Joseph L Hora Updated April 1996 The MIRAC data files can be directly converted to FITS files and reduced using IRAF and several stand alone C programs Below is a sample log of an IRAF session where an image of Alpha Tau was constructed from several MIRAC observations All IRAF commands below are on lines beginning with the IRAF prompt cl gt and at the end of the line I have put a colon and command line number e g 1 At the end of the log are comments for every numbered line Commands that begin with the exclamation point are external commands or programs In several places I cut out program output lines to save space this is indicated with three lines containing periods such as in command 4 below The reduction below contains everything necessary to go from the raw data to the final star image A number of steps such as constructing the gain and mask images need only be done once per
102. 08 29587 28296 27682 21234 5 50 475 409 246 235 230 1 77 1357 1030 937 980 937 917 771 781 687 591 428 409 400 30 124 109 937 815 779 762 585 20 180 33 8 341 9 8 168 69 2 30 5 99 1 Tenue A 5195 D VITIA 45 22 99 2 Standard IR Stars 111 A2 2 Notes on Standard Stars The following notes on mid infrared standard stars was provided by Marc Kassis The notes give the Bayer Greek letter name followed by the Bright Star Catalog 2 s estimation of the star s variability and basic data presented by the SIMBAD data base A collection of comments follows each standard star entry Star Bright Star Cat SIMBAD Alpha Aql High proper motion star Alpha Ari Suspected Var Var Alpha Aur Suspected Var Var of RS CVn type Alpha Car Star Alpha Spectroscopic Binary Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star Alpha CMi Suspected Var Spectroscopic Binary Alpha Her Var Double or Multiple star Radial velocity variations with a period of 1 yr were detected by Smith et al 1989 AJ 98 2233 Alpha Hya Suspected Var Var Larson et al 1999 ASP Conf series find that this star has radial velocity variations on the order of 1 to 2 years Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assemb
103. 09 88 inch HP office 933 4104 88 inch summit 974 4200 88 inch summit fax 974 4202 242 MIRAC User s Manual Infrared Telescope Facility Office 808 956 8101 Institute for Astronomy Fax 988 3893 2680 Woodlawn Drive Honolulu HI 96822 Div Chief Robert Joseph joseph hubble ifa hawaii edu Sec y Karan Hughes hughes hubble ifa hawaii edu IRTF Office 808 974 4205 P O Box 4729 Fax 974 4207 1175 Manono St Hale Pohaku 974 4213 Bldg 393 Fax 969 7624 Hilo HI 96720 Summit 974 4209 Fax 974 4212 Joint Astronomy Center Office 808 961 3756 660 North Aohoku Place Office Fax 961 6516 University Park Hale Pohaku 933 4105 Hilo HI 96720 Summit UKIRT 961 6091 UKIRT Dir Andy Adamson a adamson Gjach hawaii edu Summit Fax 935 0221 Sec y Anna Lucas jach hawaii edu Engineer Caltech Submillimeter Observatory Hilo 808 935 1909 P O Box 4339 Summit 935 9853 Hilo HI 96721 Summit Fax 935 2708 5 22 99 24 Addresses and Telephone Numbers 243 Appendix 24 Addresses and Telephone Numbers Name email phone fax Address MIRAC http cfa www harvard edu jhora mirac html Aditya Dayal adayal ipac caltech edu IPAC Work 626 397 7320 Mail Stop 100 22 Home 626 792 2312 770 South Wilson Avenue Lynne K Deutsch Giovanni G Fazio William F Hoffmann Joseph L Hora Richard Florence Fax 626 397 9600 deutschl bu edu Work 617 353 2633 Home 508 266 264
104. 145 Ibs 10 6 93 Power Supply Gray Duct Tape 12x26x24h 81 Ibs 10 6 93 Computer Yellow Fiberglass 28x28x16h 110 156 10 6 93 Monitor and Files Yellow Fiberglass 18x34x22h 86 Ibs 10 6 93 Cryostat Gray Polypropylene 40x22x26h 103 Ibs 7 9 93 2 27 96 Transfer Tube Cardboard Carton 25 165 74 21 7 2 27 96 9 crates 842 52 790 Ibs 5 22 99 13 3 Shipping Labels for UKIRT Steward Observatory University of Arizona 933 N Cherry Ave Tucson Arizona 85721 Phone 602 621 6529 Attn William Hoffmann Joint Astronomy Centre 660 N A ohoku Place Hilo HI 96720 Phone 808 935 4332 Attn Andy Adamson A13 Shipping Procedures and Shipping Inventory 165 Steward Observatory University of Arizona 933 N Cherry Ave Tucson Arizona 85721 Phone 602 621 6529 Attn William Hoffmann IRTF 1175 Manono St Bldg 393 Hilo Hawaii 96720 Phone 808 974 4205 Attn Paul Jensen 166 MIRAC User s Manual A13 4 Shipping Inventory and Packing Packing instructions are given in Sections 5 3 and 5 4 Items are listed in order of packing inverse order for unpacking Volume and weight of 8 crates are 56 cubic feet 748 Ibs The foam in each crate is labeled with the crate number and the foam layer number 1 on bottom The foam should be placed in order in the lid as it is removed from the crate and returned to the crate in order before storing the empty crate The individual items are labeled with the
105. 2 Fast Data Mode SUP 71 9 9 3 Ultra Fast Mode 71 910 Telescope Control ec recria as eg er basa 72 9 10 1 Nod Control by Logic 1 12 9 10 2 RS 232 Control of the Telescope 72 9 10 3 Ethernet Control of the Telescope 73 9 10 4 Offset Modes and Taking Data 74 5 23 99 Contents 11 10 Mask Gain and Plat Field YR 75 TU T PESE eR KR bx Y 75 10 2 Map Generation 76 10 3 Pr paring a Hat Field 222255552299 Oa Gi 76 10 4 Using the Mask Gain and Flat Field maps 77 10 5 Principles of Mid Infrared Flat Fielding 77 11 Reading Stored Data and Data Processing 79 11 1 Methods of Loading Data 79 C rrent Observation x oy ia ees 79 11 1 2 Accumulated Observation 80 1 1 3 Replay Mode erento ORGAO EA ARGOS 80 522 ees Seta e keep ewe 80 MOSAIC e acd e eee ge
106. 22 99 14 Hardware Preparation and Setup 181 the start of the cooldown If the chambers are topped off with LN around five after the fill the inner will hold for 48 hours and the outer for 15 hours A plot of the LN cool down is given in Figure 14 2 300 250 200 Temperature e Outer 7 Funnels LHe Transfer Inner 10 Funnels 0 00 1 00 2 00 3 00 4 00 5 00 6 00 7 00 8 00 Time hours Figure A14 2 Cryostat Cooldown 14 3 4 Liquid Helium Cool Down The liquid helium cool down can be started any time after the detector temperature sensor is close to 80 This can be estimated from Figure A14 2 or determined by starting the MIRAC program and turning on the MIRAC Power Supply Temperature Monitor Switch Section 6 1 The remaining LN in the inner chamber must be first removed by transferring it out to the 4 liter transfer dewar using the LN removal fitting and tubing and a source of pressurized gaseous dry nitrogen or helium With a pressure of a few oz one liter of LN can be removed in 5 minutes The gas flow through the fitting should be continued for an extra 1 or 2 minutes to insure there is no LN remaining in the chamber The LHe transfer is carried out with a vacuum transfer line The minimum dimensions of the transfer tube are length of tubing into cryostat 11 7 inches separation between the cryostat and supply dewar tubing 17 25 inches xxx plus the radius of t
107. 4 5 The range of magnification for the MMT is 57 pixel scale 28 arcsec pixel and field 36 arcsec to 1 14 pixel scale 14 arcsec pixel and field 18 2 arcsec Table 14 5 Cryostat Magnification Slide Position Magnification KnobGap Case Faceto Telescope cm Focus cm Out down 6 3 1 43 6 2 7 1 S O 1 5 2 3 m IRTF UKIRT 2 46 6 0 6 0 3 ol 5 6 4 4 2 4 57 5 2 2 9 6 5 m 5 80 3 5 8 6 1 0 2 0 2 7 7 1 14 1 0 3 6 8 CAUTION IF THE MAGNIFICATION ACTUATOR DOES NOT MOVE SMOOTHLY TO THE HIGHEST POSITION DO NOT FORCE IT THERE MIGHT BE INTERNAL CABLE INTERFERENCE A14 9 TV Relay Optics Pupil Setting This involves selecting installing aligning and focusing the correct pupil stop This is done with the telescope mirror cover open with a bright background behind the telescope secondary This can be a brightly lighted white dome or the daytime sky The guiding TV should be removed from the guider box The guider box optics should be in the low magnification position Step 1 Choose the appropriate pupil stop The pupils are located in a small envelop in the Camera Mounting Tools and Screws parts box The S O 2 3 m pupil is 067 or 072 in The IRTF pupil is 081 or 087 in Loosen the pupil clamping plate screws and slip the pupil stop under the clamping plate Step 2 Using a jeweler s loop to view the pupil and the image of the secondary created by the TV relay optics adjust the position
108. 5 Fax 617 353 5704 fazio cfa harvard edu Work 617 495 7458 Home 969 8055 Fax 495 7490 whoffmann as arizona edu Work 520 621 6529 621 7928 Home 323 0814 Fax 621 1532 cfa harvard edu Work 617 486 7458 Home 243 9973 Fax 495 7490 richard a florence boeing com Work 714 762 4553 Fax 714 762 0844 Pasadena CA 91125 Astonomy Department Boston University 725 Commonwealth Ave Boston MA 02215 Center for Astrophysics 60 Garden Street MS 65 Cambridge MA 02138 Steward Observatory University of Arizona 933 N Cherry Avenue Tucson AZ 85721 0655 Center for Astrophysics 60 Garden Street MS 65 Cambridge MA 02138 The Boeing Compamy Autonetics Guidance Navigaion amp Sensors 3370 Miraloma Avenue P O Box 3105 Anaheim CA 92803 244 MIRAC User s Manual 5 22 99 2 3 m 11 19 21 41 47 48 72 99 104 170 183 186 188 195 198 200 201 236 237 absolute 24 73 74 151 229 accumulated observation 80 add 36 71 81 97 104 120 122 132 229 235 236 addtess 1 163 239 243 addresses 3 13 164 241 243 airmass 19 22 50 71 76 78 101 105 119 123 124 133 134 136 138 140 141 143 144 172 177 aligning 93 94 105 186 195 Alt 21 31 35 42 53 60 65 67 162 227 ACE keys vie oe Sie 42 67 analog 4 62 93 170 176 210 arcsec 4 6 9 11 24 25 34
109. 6 118 119 123 125 127 131 132 134 137 140 143 144 159 170 227 231 233 235 238 DISP 24 25 33 48 50 62 66 72 74 77 79 80 82 84 89 90 96 98 102 145 152 153 155 157 158 161 162 197 201 display 4 24 25 31 33 39 42 43 50 60 62 64 66 71 72 74 75 79 91 93 95 97 98 101 102 104 123 125 127 152 156 158 161 192 194 197 201 208 227 232 11 81 divide iue du 97 140 141 519 21 23 31 32 34 36 42 46 50 53 54 57 59 60 72 73 81 96 119 123 143 170 227 235 DOS shell 32 42 44 96 DSP 4 31 34 35 62 63 71 72 101 102 143 145 148 161 205 em il cse REX E 13 15 163 243 dad ete 65 ethernet 4 15 16 19 23 24 73 89 151 170 183 191 exit 31 32 37 65 96 137 154 157 235 236 expansion factor 81 95 fast data 23 71 72 96 104 D qM 17 241 243 file transfer 100 227 7 9 27 28 34 35 39 43 45 59 66 67 76 78 105 107 115 117 133 135 136 143 144 147 148 150 168 170 173 176 191 192 194 219 224 226 filter wheel 34 67 116 135 173 194 219 224 226 FIT25 29 48 50 62 66 80 85 87 90 103 152 157 FITS 6 42 61 72 83 95 96 99 100 107 131 135 137 140 141 150 158 201 flat field
110. 6 1 13 10 12 5 11 9 13 07 1 16 10 17 4 17 17 17 63 45 026 17 8 17 57 18 03 46 026 18 17 1 18 9 1 8 10 20 6 19 9 21 3 1 4 068 7 6 10 013 TI 11 8 6 13 014 79 12 10 0 17 017 79 13 12 5 21 017 65 14 14 5 21 014 42 10 2 5 16 Array MIRAC System Properties The array and system properties for the detector at 5 0 K are given in Table 2 3 G is the mean electron gain p is the dispersion in the gain over the array It is desirable to keep the sky background flux in the high leakage pixels less than the maximum linear range and the average background greater than the background at which the BLIP noise is at least twice the zero background system and readout noise For very low background filters such as 2 2 um this might not be achievable because the high dark current pixels will exceed the linear range at frame times greater than 140 msec 8 MIRAC User s Manual The BLIP noise is given by BLIP Noise background electrons x 2 1 Table 2 3 HF16 Array and MIRAC System Properties at 11 7 um Array temperature 5 0 K Detector substrate bias 3 0 V Detector bias 2 0 V Read time 1 1 msec Transimpedance array output input 096 u V electron Transfer preamp input to A D output 305 mV digital unit Transfer array input to A D output 3191 electrons digital unit Effective input capacitance 1 7 picofarad System A D toggle rms noise at A D 41 digital units referred to preamp input 125 mV A
111. 8 6 0 62 35 2530 059 25 34 7 9 9 8 0 69 20 3210 11 38 58 7 1 10 3 0 73 20 2750 082 27 42 7 4 117 0 83 20 2550 080 25 43 7 1 12 5 0 88 20 3200 071 25 44 6 9 106 0 75 6 6 3700 050 11 17 8 2 17 4 1 23 39 3160 1 8 890 2090 2 0 17 8 1 26 31 18 1 27 4 4 3700 75 160 390 3 8 20 6 1 46 8 7 3000 2 0 456 1230 22 8 8 0 62 70 1200 CVF 10 3 0 73 70 1460 CVF 13 5 0 95 35 2590 Measurement settings Magnification 41 IRTF pixel 34 arcsec Bandwidth 71 usec Burst Mode Read time 2 2 msec The frame times are chosen for background within linear range and for noise to be background shot noise limited Section 7 3 The background scales directly and the sensitivity Jy unit inversely as the frame time The noise is for chop nod source in one beam one minute total time except for 2 2 and 3 8 um which are chop only The point source noise is determined from the surface brightness noise by assuming 1 2 the signal appears in a disk of the root sum square of the diffraction FWHM and seeing FWHM taken to be 5 arcsec For the Steward Observatory 2 3 m UKIRT 3 8 m and MMT 6 6 m telescopes the sensitivity in Jy unit should be multiplied 1 7 64 and 46 respectively and the noise in mJy arcsec by 1 3 8 and 46 respectively 5 23 99 2 Overview Performance 11 Additional notes to Table 2 4 1 The observed image FWHM is determined by diffraction telescope aberration chopper distortion and seeing At the IRTF the latter
112. 88 MIRAC User s Manual Options DOLI EE Redraw Value Hardco Output Exit 30 70 5 20 10 0 1 2 3 4 6 7 3 10 Radius Gaussian Fit Peak 7 469E 1 Pos lt 63 98 64 02 gt FWHM 3 00 Const 3 942E 1 ChiSar 1 200E 1 OBS 4 05 96 15 33 00 c960405a 001 SIMULATED STAR IDLE 0 00 0 02 5 DISP 4 05 96 15 16 57 76 Data not saved SIMULATED STAR Mode Current Figure 11 5 Radial Plot of Simulated Star with Gaussian Fit to Profile 11 2 7 Plot Command Line Options The Plot command line has various options that allow the user to change the way the data is displayed to examine the data and to print a copy of the plot on a printer The sections below describe these commands There are two kinds of plots one dimensional 1 D such as Slice or two dimensional 2 D such as Grayscale The commands that are available in only one of the modes is marked with either 1 D or 2 D otherwise the command is available in both menus and is not marked 11 2 7 1 Setup This menu allows the user to change the way the plot is displayed on the screen with a number of submenus and commands Display Size Limits Style In this menu are such things as setting the location of the plot on the screen the range of data that is displayed and whether to use log or linear plot scales and to autoscale the X and Y axes This menu also permits selecting the color of the plot labels and plot grid The position 1 1 i
113. 94 12 3 Camera Control and Testing 94 124 AS CUMMUIDUL 153 PHI 95 12 5 FITS FIE OQutp t ee 95 12 6 DOS 96 12 7 Unpack Fast Data and Ultrafast Data Files 96 12 89 Rebuild L g File 225p ey ers saw Ge e se ICD ee Y S e 97 12 9 Arrange data into lines or image 97 12 10 Exchange columns to fix image 97 12 11 Standard Deviation calculation 97 iv MIRAC User s Manual 12 12 Display Image Arithmetic 97 13 Post Processing Images e ee eee eee ee eds 99 13 1 Converting files to PITS 99 13 1 1 Converting using a unix 99 13 1 2 Using the MIRAC3 program to convert to FITS 99 st 99 13 5 Further Conversion of Files 100 Glossary of Terms vesci sai e arse CER taints 101 Appendix 1 Principles of Mid IR Observing 103 A1 1 Mid IR Observing with Chopping Nodding and Offsetting 103 1 2 Integration Times Chop Nod Options
114. A 8 8 pm Second wheel Open 9 8 yum Third wheel Open Cy 10 3 qm CVF positioning D 11 7 yum Precise control gt E 12 5 Turn off motor current F Open Init Filters Gs 7 2 0 6 Q3 Magnification 0 439 H 10 6 N Arcsec Pix 0 340 I 7 9 ME Wavelgth file filtpl txt J CVF Start Go to next CVF wavelth e Reset CVF Wavelth file Enter Pupil Info 36 IRTF p Second Wheel 5 A Open Precise Control 18 0 Qshort Els 0 F2 0 F3 0 C 17 4 QO Active wheel 1 D i729 Ql Step increment 1000 Forward Move 4 8 Backward Move G 2 2 K Go to a position H Pupil Imaging Home I 20 J Turn controller power J 2 K Shut Motor drive off L Turn Motor drive M Turn off controller power N HomeSW Position 148 MIRAC User s Manual Wheel p Magnification A Open 43 Blank 46 Cs Can 252 D Dies SF E 5080 1 00 1 14 G Enter value 0 43 Js Pupil Info A Blank B 45 SO 1 5 2 3 m C 36 IRTF UKIRT D 30 CTIO 4m E f 16 SOFIA 15 6 5 m r Hardware Settings z A Init COL subarray 1 0 3 0 p E Bandwidth Time Com B End COL suba
115. All Arguments Last Argument First Argument 2 n th Argument Arguments x Through xy Modifiers Print Command Line Substitute Command Line g s 1 r 3 2 Aliases alias Command alias name definition definition can contain escaped history substitution event and word designators as placeholders for command line arguments 3 3 Variable Substitution Creating a Variable set var Assigning a Value set var value Expressing a Value var Displaying a Value ech var value is a single word an expression in quotes or an expression that results in a single word after variable filename and command substitution takes place Assigning a List set var list list is a space separated list of words or an expression that results in a space separated list Selecting the Item var n Selecting all Items var Selecting a Range var x y Item Count var 3 4 foreach Lists Start foreach Loop foreach var list foreach prompts for commands to repeat for each item in ist with gt until you type end Within the loop var stands for the current item in list 3 5 Command Substitution Replace Command with its Output on the Command Line 3 6 Job Control Run Command in the Background amp Stop Foreground Job Control Z List of Background Jobs jobs Bring Job Forward Resume Job in Background n 4 Processes Listing ps aux Terminating kill 9 PID Timing time command Scheduling at time a p sc
116. Assembly plastic box remove the six screws Place the screws and washers in the Guider Box Assembly plastic box 24 Lower the table with the guider box Screw the cover plate over the round hole in the top of the guider box 25 Return to Guider Box Assembly plastic box to the MIRAC table in the control room Store or pack in Crate 1 the guider box Final Control Room Tasks 26 After the cable at the telescope is disconnected and retied the following should be done in the control room as protection for the equipment 1 unplug the camera computer and monitor AC power cords 2 disconnect the BNC chopper cable at the barrel coupler near the computer 3 disconnect the network connect at the back of the computer Packing the Cryostat 27 If the cryostat is to be packed it should be packed in MIRAC Crate 7 a gray Polypropylene crate 28 The window cover should be over the cryostat window 29 The LN2 and LHe caps should be on the LN2 and LHe vent fittings with the tubing aligned with the arrows on the cryostat top 30 Put the white foam top protective cover on the cryostat taking care the vent tubing is aligned in the cutouts in the foam 31 Place the cryostat in the bottom protective cover taking care that the LN2 vent tube is aligned in the cutout Secure with the two short Velcro straps 32 Wrap the cardboard vest around the cryostat with the two handles coming through the handle holes in the vest Note the marked win
117. Begin StDev calculation Jl A12 3 2 UTIL Arith Add constant Subtract constant Multiply by constant Divide by constant Invert map Justify map Boxcar Smooth Map X Flip Row Y Flip Column Transpose 160 12 3 3 UTIL Macro F m Macro Menu MIRAC User s Manual Display Macro Definitions Begin Macro from disk Assign Macro to key Remove Macro assignment Save current Macro to file File Dir of Macros o mrm 1 2 F4 F6 E print savefits findstar stdparm objparm disparm F8 None defined None defined F9 None defined F10 savrdrun Press any key to continue Current Macro Definitions 4 Assign MACRO to Key Enter F key to assign macro 1 10 valid We A12 3 4 UTIL Temp l DTVolts 0 HeatVolts 0 Ambient 0 Electr 0 A DTemp V 0 LN2Temp V 0 Temperatures Enter ms delay between samples 1000 0012 0012 0012 0012 0012 0012 5 000 0 0000 10 22 23 54 45 07 76 33 lll 5 22 99 12 3 UTIL Command Line Menus 161 A12 3 5 UTIL Scope Scope Display First display column 1 Second display column 128 Edit Scope Header gt Change Display Params Scopdic spc Offset for second trace 0 000 Dble2S
118. C display O units is always 0 flux and the linear range is identical for all offsets The variable offset is adjusted with a pot on the first board in the preamp box The values of these offsets are given in Table A17 10 The 16 output channels are interleaved on the array in a 2 column by 8 row block as shown in Figure A16 4 The figure shows the 2x8 pixel blocks with line numbers and indicates row and column numbers and array pin numbers at the array corners in brackets Also shown is the location of the temperature sensing resistor on the chip carrier Each of the pixels in a block are read at the same time The pixels are reset in groups at a time after the whole group has been read out The eight blocks in the lower half of the array are reset together while the first two blocks in the upper half are read and the eight blocks in the upper half reset while the first two blocks in the lower half of the next pair of columns are read This makes it impossible to operate this array in a double sample mode whereby each pixel is read both before and after resetting Since this array is usually operated at high flux with the noise of each read dominated by photon to electron conversion shot noise suppression of read 1 f noise by double sampling is not required However this resetting method necessitates a special approach to burst mode fast read of the array after a slow integration period by which the bias voltage VDDR is clocked in order to inhibit th
119. C team several days prior to the telescope deadline to allow time for their inputs This can be done by email to the addresses below in either TeX or postscript format This list below gives the names street addresses and e mail addresses of the five of the team members The affiliations as they should appear on publications which include MIRAC3 are also given Aditya Dayal IPAC M S 100 22 California Institute of Technology 770 S Wilson Ave Pasadena CA 91125 adayal ipac caltech edu affiliation IPAC Caltech Lynne K Deutsch Astronomy Department Boston University 725 Commonwealth Ave Boston MA 02215 deutschl bu edu affiliation Astronomy Department Boston University Giovanni G Fazio Harvard Smithsonian Center for Astrophysics 60 Garden Street MS 65 Cambridge MA 02138 fazio cfa harvard edu affiliation Smithsonian Astrophysical Observatory William F Hoffmann Steward Observatory University of Arizona Tucson MA 85721 hoffmann as arizona edu affiliation Steward Observatory University of Arizona 14 MIRAC User s Manual Joseph L Hora Harvard Smithsonian Center for Astrophysics 60 Garden Street MS 65 Cambridge MA 02138 jhora cfa harvard edu affiliation Smithsonian Astrophysical Observatory 3 2 Observatory Arrangements Many details for observatory arrangements can be found in the Observatory home pages given in Section 2 1 3 2 1 Kitt Peak Arrangements Arrangements for Kitt Pea
120. CH A B SELECT CH A CHB _ MEM OUT ENABLE A B COADD IN LATCH WRITE 1 pl 0 8 16 24 32 Bit Clock Cycles Figure A16 7 Signal processor pixel timing ARRAY READ amp COADD ARRAY RESET w CHOP WAIT pede ee ebbe PIXEL INTEGRATION WRITE COADDER OUTPUT TO COADDER MEMORY TO FIFO MEMORY CHOPPER DRIVE SIGNAL DATA READY SIGNAL 4 100 5 msee _____ gt 0 20 30 40 50 60 Array Read Cycles Figure A16 8 Array read timing with chopping 70 80 90 00 16 FIFO s to the digital signal processor in the PC taking about 17 msec for the data transfer while the next chop half cycle is taking place 212 MIRAC User s Manual 213 ostat Inputs and Outputs 17 Cry 5 22 99 Appendix 17 Cryostat Inputs and Outputs B d He 34133313 LLL LLL 1 BEERS EE 414141 7 4 1011 144115 133 urgqiidi 23d ees sus PG GEEEEEEEE TET rr Table A17 1 Bia ee Detector Cold TEEEEREEEEHLL scd cos gan SE
121. D 8 7381 D 8 5 psec E 17 4763 E 17 2 usec F 34 9525 E 34 1 psec G 69 5067 G 68 3 psec H 139 1810 H 136 5 psec 5 22 99 A12 1 OBS Command Line Menus 147 of 5 MGR and Chop Paramet Variable Nod Wait Time On src sec 3 00 Low Off src Nod Wait Time sec 2 00 Medium Wait time chopper ms 4 369 High evel of Off Src Chop beam 0 Source Source Name ALPHA BOO Comment Image coordinate parameters gt R A of Object 14500322775 coordinate Dec of Object 19426730795 Epoch of Coordinates 1950 00 Initial Column T List of sources O GALSHORT DAT B Initial Row 18 Find source in list C End Column 128 Airmass 1 576 D End Row 128 Get current standards E Offset Columns 0 000 Put current source in list F Offset Rows 0 000 F Search for current standards 3 ALPHA BOO 14 13 22 75 19 26 30 95 1 4440 ALPHA SCO 16 226 20 21 26 19 21 95 1 5155 ALPHA HER 17 12 22 00 14 26 45 00 1 0073 GAMMA DRA 17 55 26 50 51 29 37 00 1 1794 GAMMA AQL 19 43 52 90 10 29 24 00 1 1994 MU CEP 21 41 58 50 58 33 0 00 1 9492 End of search Press key to continue Filter Settings 5 p First First wheel 8 8
122. G STRAPS FOR SUPPORTS 3 PLACES HELIUM VESSEL LID SUPPORT TRIANGLE HEAT EXCHANGER FOR SUPPORTS HELIUM VESSEL COLD PLATE STRAPS FOR ARRAY INTERFACE PLATE SHORT COLD SHIELD BIB ARRAY MOUNT ARRAY SLIDE LINEAR CROSS ARRAY UP POSITION 4K SHIELD 77K SHIELD 1 POSITION FILTER WHEEL 8 POSITION WHEEL FILTERS Cy CVF WHEEL APERTURE SLIDE FILTER WHEEL MOUNTING PLATE FLAT MIRROR 4K BAFFLE 77K BAFFLE MIRROR WINDOW GETTER CONTAINER SHIELD SHUTTER FLOATING SHIELD VACUUM GLAND FOR APERTURE SLIDE VACUUM GLAND FOR SHUTTER VACUUM GLAND FOR ARRAY SLIDE WITH INDICATOR VACUUM VALVE FERROFLUDIC FOR FILTER WHEELS 3 EACH 2 010 STYLE ONE NEW DELRIN COUPLER MOTOR DRIVE STAND Figure 2 2 Drawing of MIRAC3 cryostat 6 MIRAC User s Manual A C program is available for processing the files stored in MIRAC format combining the chop and nod images applying a mask and flat fielding corrections and producing image files in FITS format Typical one sigma sensitivities at the IRTF are 26 mJy arcsec at 11 7 um 1096 bandwidth 480 Jy arcsec at 20 6 um 6 8 bandwidth and 70 Jy arcsec with the 2 bandwidth CVF in 1 minute total time chop nod with the source in one of the four beams 2 3 Magnification and Pixel Scale The magnification can be zoomed from 43 to 1 14 with seven positions located by detents Table 2 1 gives the magnification pixel scale field size and wavelength for
123. MIRAC3 USER S MANUAL Steward Observatory University of Arizona Harvard Smithsonian Center for Astrophysics William F Hoffmann Joseph L Hora Manual Version mrcman91 99w wpd May 22 1999 Program Version 7 22 May 3 1999 readme txt May 22 1999 This readme txt file dexcribing the MIRAC3 Users Manual and the gzip postscript MIRAC manual files can be found in kepler as arizona edu anonymous pub mirac The current version of the MIRAC Users Manual mrcman91 99w wpd was completed May 22 1999 This version has been updated for the hardware and software changes in MIRAC3 and includes corrections and additional material on standard stars filters and operation and troubleshooting the camera Send comments to whoffmann as arizona edu The following gzip compressed Postscript files contain the manual The postscript files are printed with a binding offset for double sided printing File Chapters Pages Compressed Uncompressed mr01x02 ps gz Contents 2 Title 12 319562 1494992 mr03x10 ps gz 3 10 13 78 610574 2786308 mrllix13 ps gz Ll L8 79 102 264316 2531688 mra01x10 ps gz Al A10 103 142 678263 3958165 mrallxi13 ps gz 11 A13 143 178 122065 518709 mral4xi5 ps gz 14 15 179 204 2409854 6116263 16 19 5 42 16 A19 205 226 215722 1586640 mra20x24 ps gz 20 24 227 249 107361 403727 readme txt MIRAC Manual Organization The MIRAC User s Manual provides information and che
124. Manual 8 2 The aircor Program The aircor c program applies an extinction correction to a range of FITS format data files using the user supplied correction factor and the value of the airmass in the file header specified by the FITS keyword AIRMASS The compiled C program can be obtained from the MIRAC home page the WWW Section 2 1 The files should already have been masked and gain corrected The data in the files will be multiplied by a factor to correct the image values to an airmass of 1 0 based on the value of the airmass given in the data file header The capability to override the header value is provided in case this the object name hence RA and Dec was not correctly entered at the time of observing To compile the program two other files besides aircor c are needed fitsio c and fiocom h All three files should be placed in the same directory and the following command executed to produce the executable file aircor cc aircor c fitsio c Im o aircor Usage aircor filename extfact f r n1 n2 where filename is the full name or root name of the file or files to be processed For example a single file name is 1920604 453 a root name is 1920604 extfact is the extinction factor to be used The data values are corrected by applying the following formula to each pixel value newval oldval 10 extfact Airmass 1 0 2 5 Options f is the option to force calculation of the airmass if the header is inco
125. N cool down close the cryostat vacuum valve and remove the vacuum pumping line The LN2 shutter should be closed up position Set the pupil slide and magnification to the positions desired for observing run Make sure that the three actuators are fully withdrawn See Section A14 8 for detailed instructions The cool down is carried out by pouring LN from a 4 liter LN transfer dewar into the MIRAC inner and outer cryogen chambers with two 0 7 liter metal funnels fashioned from army canteens One has a 14 inch tube for the inner LHe chamber and the other a 6 inch tube from the outer LN chamber The black plastic rods should be kept in the funnel tubes inserted from the tube opening for protection at all times when not transferring The same rods are inserted into the tube funnel end to stop the LN flow when the cryostat chamber is full It requires about 7 funnels full 5 liter for the outer and 10 funnels full 7 liter for the inner over about 50 minutes to cool down and fill the cryogen chambers Transfer into both chambers at the same time starting with the outer In between transfers and when the chambers are filled the two foam tubes should be placed on the cryogen fittings to direct the cold boil off gas away from the cryostat top surface The first charge lasts about 12 hours for the outer chamber and more than 48 hours for the inner chamber if the outer is not refilled The detector assembly will reach 78 K in about 5 hours after 5
126. Plot Levels gt Gray level scaling gt Printer setup gt Save Parameters MRC SPC Read Parameters MRC SPC Contour Grayscale Values Slice Frequency Histogram TableStDev Radial Default XHexValues p Contour Plot Levels evel 1 0 5000 evel 2 1 0000 evel 3 1 5000 evel 4 2 0000 evel 5 2 5000 Level 6 3 0000 evel 7 3 5000 evel 8 4 0000 evel 9 4 5000 evel 10 5 0000 evel F 5 5000 evel 12 6 0000 156 MIRAC User s Manual f Display size limits styl F Labels of plot A Max X data 10 00000 X Axis label B Min X data 1 00000 Y axis label C Max Y data 10 00000 Plot Title D Min Y data 1 00000 A Places LEFT of the dot X 4 E Left X 100 B Places RIGHT of the dot X 0 Right X 600 C Places LEFT of the dot Y 4 F Bottom Y 400 D Places RIGHT of the dot Y 0 Top Y 20 major tics 5 I Log X axis labels Off F of Y major tics 4 J Log Y axis labels Off G Length of X tics 4 K Auto X Axis limits On H Length of Y tics 5 L Auto Y Axis limits On Ix of X minor tics 5 M Color of labels White de of Y minor tics 5 N Color of grid White K Length of X minor tics 2 Length of Y minor tics 2 level
127. R PC The monitor power should automatically come on If a floppy disk is in the floppy drive it must be removed Computer should boot connect to the network set the PC time from the network and show the DOS prompt If computer was running a tape backup exit backup program if necessary At keyboard type MIRAC enter This will reset the computer time from the network load the DSP Digital Signal Processor program and start the MIRAC program Turn on Temperature Monitor left hand switch on MIRAC power supply in aluminum suitcase Two green LEDs at the power supply should come on Confirm that DetTemp on monitor status display is 3 9 K Mauna Kea or 4 3 K sea level If it is above these values cryogen has run out and must be tended to before turning on the camera 3 Confirm that the time on the MIRAC display is the same as the Telescope Control Computer time The PC time is set from the network each time it is booted and each time MIRAC is run It can be reset at any time For the PCNFS network software Steward Observatory and IRTF execute TIMES or RDATE host where host is the name of the observatory host computer bok planck etc 4 Transfer cryogens into MIRAC cryostat Follow instructions in Appendix 15 32 MIRAC User s Manual 5 Update observing directory If this is the start of a new program during a MIRAC run copy new catalog command and offset files to the observing directory as required Section 5 2 I
128. RAC computer is not connected to a network the FITS files will have to be transferred to a floppy disk in order to transfer the files from a computer that is on the network On the SO 2 3 m telescope the PC under the table at the observer s station is connected to the observing SUN 100 MIRAC User s Manual computer BOK The ftp utility should then be used to transfer the files to BOK The following is a sample transfer session The commands that are typed in by the user are underlined the text on the right side are comments Sample file transfer session from PC to SUN C N ftp bok begins file transfer program Connected to bok as arizona edu 220 bok FTP server SunOS 4 1 ready Name bokobs user name for observers 331 Password required for bokobs Password type in current password here 230 User bokobs logged in ftp type binary sets binary transfer mode 200 Type set to I ftp prompt i will not ask for each file it will Interactive mode off transfer all matching files ftp mput f91 put files from PC to SUN files in default dir on PC messages for file transfer ftp quit end ftp session gt 13 3 Further Conversion of Files Once the files are on the remote computer there is usually another operation necessary to put the files in the proper format for that program On IRAF the files must be read in to IRAF format using the command rfits in the dataio package The following command sho
129. RE EHEER 43144 NBI 214 MIRAC User s Manual Notes to Table A17 1 Measurement settings Burst mode no Read time xxx Frame time xxx Chop wait xxx Flux level medium Flux xxx DET SUB and VRST 43 pa at 6x10 ph cm sec linear range 1 7 x 10 e at 1 msec frame time Detector bias VDI 1 V DET SUB VDD1 8 VDD9 16 and VSOURCE current depends on the input flux and the output load 16 VOUT VSOURCE RLOAD For RLOAD 30 K VSOURCE m5 Hh 6 255 V Integrated Charge Empty Full Empty Full Empty Full VOUT 4 45 2 10 4 45 2 10 4 45 2 10 V ISOURCE 4 35 3409 3 23 1 97 2 08 83 mA Power Dissipation Pdigital 9V 7 6 24 2 1 pA 4V 5 8 4 7 8 pA 4 4 4 4 4 4 mW Pbus 6V 2 45V 1 7 mA 5 30 5 30 5 30 5 30 5 30 5 30 mW Poutput 5 6V VOUT ISOURCE 5 00 10 80 3 71 6 90 2 39 2 90 mW Ptotal 141 2 17 20 9 9 L3s4 8 6 9 1 mW Operating the Array at Room Temperature The array can be operated at room temperature with different bias settings The bias box cover must be opened Set bias switches Normal Room Temperature 54 1 Off Switch bypass for DSUB 24 3K series resistor SW 2 Off Switch bypass for DETG 100K series resistor Set biases 6 VDI 6 00 5 49 9 DETG 5 00 4 78 12 DETS 3 00 4 59 4 10 4 95 Det Bias VDI DETS 1 V Cold Det Bias VDI DETS 6 V Warm VDI should be adjusted for l
130. SUBARRAY COL STAR SUBCOLND 3 SUBARRAY COL END ARYCYCTM 1 092266640626 03 ARRAY CYCLE TIME SEC BURSTMOD 1 BURST MODE 1 ON 0 OFF COMMENT DATA HAS BEEN REARRANGED INTO ROWS AND COLUMNS FLUXOFST 3 368000000000 03 FLUX OFFSET VALUE COUNTS RAWMIN 1 632423583984 03 RAW ON SOURCE DATA MIN RAWMAX 4 122500000000e 02 RAW ON SOURCE DATA FRAMERRO 80 TRANSMISSION ERRORS CHOP PAIR 0 FRAMERR1 0 TRANSMISSION ERRORS CHOP PAIR 1 TOTCOAD2 512 TOTAL COADDS BEAM2 FINX 64 NUM COLUMNS DATA BLOCK OF LXOFF 1 572000000000e 03 LOW FLUX MODE OFFSET VALUE MDF LXOFF 3 368000000000 03 MEDIUM FLUX MODE OFFSET VALUE HIFLXOFF 6 058000000000 03 HIGH FLUX MODE OFFSET VALUE VAFLXOFF 0 000000000000e 00 VARIABLE FLUX MODE OFFSET VALUE DARKMAX 6 600000000000 02 DARK FRAME MAXIMUM VALUE FULLWELL 7 508000000000e 03 FULL WELL VALUE 5 180000000000e 03 LINEAR MAXIMUM FLUX VALUE OBSF INUM 520 OBSERVATION FILE NUMBER 2 7 637139129639e 01 LIQUID NITROGEN LN2 RESERVOIR TEMP CDE 8 888889153324 05 DEGREES PIXEL IN R A CDELT2 8 888889153324 05 DEGREES PIXEL IN DEC 11 7 294999999829e 01 RA OF REFERENCE LOCATION CRVAL2 3 078666666396e 01 DEC OF REFERENCE LOCATION CROTAL 0 000000000000e 00 ROTATION OF AXIS 1 CROTA2 0 000000000000e 00 ROTATION OF AXIS 2 6 400000000000e 01 ARRAY LOCATION OF REF PIXEL CRPIX2 6 400
131. TS format The maximum size is limited to the display array size 256x256 The automatic masking gain and flat fielding settings do not affect these maps when read in The file name is set in the DISP LOAD menu 11 1 8 Noise This mode was written mainly as a diagnostic tool in the initial testing of MIRAC although it may have other uses The Noise mode constructs an artificial array from a series of observations taken over time The artificial array contains a single particular row or column from the series of observations The user may select which row or column is used For example if row 5 is selected then the newly constructed array will contain row five from the range of images specified Each column of the new array will contain pixel c 5 n where c is the column number and 5 n is row 5 from image number n in the series 11 2 Display Modes The following display modes are chosen in the DISP Begin menu When one of these modes is activated the main display screen is erased and the chosen screen is drawn Each of the possible modes has a similar structure the plot is located in the center of the screen with a command line on the top and a display status line at the bottom A note on orientation the main display screen data orientation can be changed using the DISP Init options of X and Y flip and indicating the directions of N and E This gives the program the information necessary to control telescope motion and to record the o
132. The setup sheet should be completely filled out each night to provide a freestanding record for that night Use the observing sheet to maintain a record of the data taking including the astronomical object and purpose camera parameters and information about each image stored The image statistics including sky flux source sum FWHM rms noise and BLIP are useful for monitoring observing conditions and determining the calibration noise level and source flux without the necessity of redisplaying the images Comments about the sky condition and quality appearance and content of the images are very important MIRAC LOG CRYOSTAT Date Local fas Page Telescope Program Capacity LN2 2 7 liters LHe 3 6 LHe Lab usage Full Empty Fraction Left Hold Time Quiescent Lab Powered Lab IRTF 23 5 6 in 30 5 6 level 60 deg tilt x 90 LN2 Shut 36hr 36hr LN2Open 36hr 36 hr 7 2 11 8 22 x 11 8 level 60 deg tilt x 67 meee 40 42 36 38 8 liters cool down and fill 4 liters per day transfer thereafter W F H May 22 1999 3 MIRAC LOG SETUP Date UT Page 2 Telescope Date Local Day Program Camera Orientation Window Points circle direction North South East West Display NESW Up Let Orientation Yes No Flip Vertical Flip Horizontal Transpose 000 Magnification Pixel Scale 0 Pupil Dichroic Adjustment Ra De 00000000000 f chop wai Chop Throw 000000000 Noa war
133. Web with the address http www jach hawaii edu homestuff weather html A22 6 CSO Tau Meter Data for Mauna Kea Mauna Kea Tau Meter and other useful data can be obtained from http www cso caltech edu CSO Hawaii Weather Page Tau Plots 240 MIRAC User s Manual 5 22 99 A23 Observatory Addresses Telephone Numbers 241 Appendix 23 Observatory Addresses and Telephone Numbers Steward Observatory 933 N Cherry Avenue University of Arizona Tucson AZ 85721 Multiple Mirror Telescope Fred Whipple Observatory P O Box 97 Amado AZ 85645 National Optical Astronomy Obs 950 N Cherry Avenue Tucson AZ 85726 Institute for Astronomy 2680 Woodlawn Drive University of Hawaii Honolulu HI 96822 Director Robert McLaren mclaren uhifa ifa hawaii edu Sec y Nancy Lyttle lyttle galileo ifa hawaii edu Dept Office 520 621 2288 Director s Office 621 6524 Fax 621 1532 Kitt Peak station 621 3359 2 3 m telescope 318 8690 Operators 318 8695 Supervisor 318 8696 Catalina Station 61 inch 520 576 1283 61 inch dorm 576 1311 60 inch 621 7931 Tucson 520 621 1558 Fax 670 5740 Mt Hopkins Station 621 7933 Fax 670 6758 Office 520 670 5701 629 6741 Tucson 520 318 8000 Kitt Peak Station 318 8600 4 m telescope 318 8620 2 2 m telescope 318 8630 Fax 318 8724 Office 808 956 8312 Fax 988 2790 Hilo office 933 4873 Hilo Fax 933 4875 Dining room 935 7606 HP fax 934 45
134. a mean gain of unity over the unmasked portion of the array When multiplied by the difference between two chop half cycles it removes the pixel to pixel gain variations in the detector array Header the set of parameters that totally define how the data is taken and the program is operating This includes all the camera operating parameters such as frame rate integration time etc observing modes such as chop and nod and other changing parameters such as time detector and electronics temperature airmass etc Some of the header parameters can be edited in the OBS Header menu When the data is saved to the disk these parameters are written to the head of the data file followed by the pixel data Header file the file that stores operating parameters of the MIRAC program The file includes all the parameters that are written to the header of the data files plus other program values such as the current data directory number of printers defined current display mode etc Image a set of coimages co added by the MIRAC array processor board Image Display Buffer the array in the program where the currently displayed image is stored If in the CURRENT display mode this array contains the calculated image from the most recent observation If in some other display mode e g MOSAIC NOISE etc the image display buffer 102 MIRAC User s Manual contains the result of that operation Image data must be in this array before it is displa
135. a value 1 to regardless of how the data was flipped on the main display screen When starting the display the user is asked which row or column is to be displayed The data are then plotted and a number of options are available The same options are present in all 1 D display modes including Slice Frequency and Histogram modes A Gaussian or Moffat fit may be performed on the data in the 1 D mode as indicated above in Section 11 2 7 3 After the fit is complete the fit function is plotted on the same plot as the data It can either be plotted with the same number of points as the data or at the maximum number 86 MIRAC User s Manual showing the interpolation between the data points The full function is drawn in cyan along with the background terms alone in red Options Setup Redraw Value Hardco Output EIJ Exit 90 0 80 0 70 0 60 0 50 0 40 0 30 0 20 0 10 0 10 0 10 20 30 40 50 60 70 so 400 110 120 130 Row Co lumn Gaussian Fit Peak 7 578E 1 Xpos 63 9822 FWHM 2 6960 Const 1 109 Linear 3 736E 2 Quadr 1 975E 4 ChiSar 1 020E 1 OBS 4 05 96 15 28 38 c960405a 001 SIMULATED STAR IDLE 0 00 0 02 0 5 DISP 4 05 96 15 16 57 76 Data not saved SIMULATED STAR Mode Current Figure 11 3 The Slice Display Mode 11 2 4 Frequency The Frequency mode was added as mainly a diagnostic tool but may have other uses It is similar to the SLICE mode but instead takes a FFT of the data in the r
136. ace with the MIRAC control room setup Leave the two screws in the holes in the electronics with some tape to keep them in place or alternatively place in the Camera Assembly box 15 With an allen wrench loosen and withdraw the captive screws on either side of the cryostat mounting plate Carefully lift the cryostat off the guider box bracket 16 Secure the cryostat window cover over the cryostat window 17 Screw the rectangular cover plate over the opening in guider box 18 Pour residual LN and LHe from the cryostat 19 Return the tools used to the Camera Assembly plastic box and return the box to the control room Removal of Guider Box 20 If the on axis TV camera has been used remove the camera from the shelf on the guider box This is done by removing the bolt underneath the shelf holding the camera in place and loosening the two locating screws on one side of the camera bracket Store the bolt and washers in the Guider Box Assembly plastic box 2 Using an allen wrench from the Guider box assembly plastic box remove the 6 socket head screws attaching the TV shelf bracket to the guider box Slide out the bracket and store the screws in the marked envelop in the Guider Box Assembly plastic box 22 Screw the small cover plate over the opening in the guider box 5 22 99 5 Start and End of Run Setup and Shutdown Check Lists 29 23 Position a lift cart under the guider box Using the large allen wrench in the Guider Box
137. acking number 800 238 5355 Federal ExpressWorld Wide Web address http www fedex com For the Tucson FedEx depot on East Columbia the FedEx Depot Gate Code is 36011 164 Useful Addresses William Hoffmann Steward Observatory UA 933 N Cherry Ave Tucson Arizona 85721 Phone 520 621 6529 whoffmann as arizona edu Leslie Feldman Smithsonian Astrophysical Obs 60 Garden Street Cambridge MA 02138 Phone 617 495 7428 feldman cfa harvard edu A13 2 Shipping Crate List Crate 1 Crate 2 Crate 3 Crate 4 Crate 5 Crate 6 Crate 7 Crate 8 Sometimes shipped Crate 9 Weight Correction Total Weight Crates 1 8 765 lbs MIRAC User s Manual Paul Jensen IRTF Bldg 393 1175 Manono St Hilo Hawaii 96720 Phone 808 974 4206 Office 974 4209 Summit jensen G herschel ifa hawaii edu Tucson Office Depot Federal Express 3601 E Columbia Tucson AZ 85714 520 294 0037 Airport Support Equipment Gray Polypropylene 90 Ibs 30x25x26h 52 Ibs 4 12 97 A complete shipping inventory is given in Section 13 4 Andy Adamson Joint Astronomy Centre 660 N A ohoku Place Hilo HI 96720 Phone 808 935 4332 a adamson jach hawaii edu Hilo Office Federal Express 500 Kalanianaole St Hilo HI 96720 Guider Box Yellow Fiberglass 18x34x22h 120 165 3 3 93 Camera Electronics amp Cryo Kit Yellow Fiberglass 18x34x22h 107 Ibs 3 3 93 Cables amp 4 liter Dewar Yellow Fiberglass 18x34x22h
138. age tempmask Warning Cannot access image tempfrst Warning Cannot access image tempframe Warning Cannot access image Image tempbigl real gt Ima tempbigl double tempbigl gt tempfrst tempbigl gt temptmsk tempbigl gt tempsqr Now processing file 1921210 200 tempbigl gt tempframe tempbigl gt tempmask 1921210 200 gt tempframe 71 200 22 105 bigmask gt tempmask 71 200 22 105 Now processing file 1921210a 201 tempbigl gt tempframe tempbigl gt tempmask Warning Cannot access image temptmsk ge 1921210a 216 gt tempframe 82 211 30 113 bigmask gt tempmask 82 211 30 113 ataull7 tempfrst tempsqr ataull7 sg4 function sqrt Image ataull7 double gt Image ataull7 real Image ataull7 sg4 double Image ataull7 sg4 real cl displ ataull7 z2 50 36 Coments 1 change directory to location of data files 2 programs and scripts to current directory 3 Initialize packages and scripts necessary for processing 4 Convert grab observations at 1 and 2 airmass to FITS files 5 Read files into IRAF files Enter any name for the IRAF filename the name gets changed to the i921210a 200 style name that is in the FITS header 6 Remove the FITS format airmass files we will not need them further 7 Make list of all the files read into IRAF 8 the list to
139. al input This a separate cable with a small metal filter box in the middle of it The small black ground shorting stub should always be in place on the branch of this cable One end goes to the electronics connector panel The cable clamping screws must be inserted and tightened snugly at the connector panel The shorting cap at the cryostat must be removed and stored in the cryostat assembly box The cable should be connected to the cryostat connector while maintaining hand contact with the cryostat to avoid static electricity sparks Temperature sensor heater from temperature monitor to cryostat temperature connector This is stowed under the electronics top cover Filter controller box under camera electronics to cryostat switch connector Filter controller to filter motor connector at base of cryostat cable clamping screws must be inserted and tightened at both ends Cable Bundle Camera End The captive beige velcro straps on the cable bundle should be opened to separate the cables near the end of the bundle The cable should be securely attached to the electronics box with the three velcro straps Power cable camera electronics power connector Note the power supply should be first turned on and the indicator lights checked while the shorting stub connector in on the cable before the cable is connected to the camera electronics Data Command fiber optic cable to camera electronics fiber optics connectors red or orange are command b
140. alculation Dos Shell Unpack FastData files Rebuild LOG file Arrange data into lines Exchange columns to fix Calculate STD DEV image gt m v gt or image image F Syst Dos Version 6 22 Memory Available Coprocessor Drive capacity Drive free space Press any key m Info 985376 using 80387 63963136 24852480 1 Column to display Output File name Frame number 0 for all Data file String Type of data output Begin Output Skyflux 5 File Output 4 Expansion factor 1 Output extension Frame number 0 Data Input files Source List ALL CAT Force AMass Calculation Off Interpolate Bad Pixels Off Begin conversion to FITS Errors of data Temp Skyflux Value RMS L output 5 22 99 12 3 UTIL Command Line Menus 159 calculation FastData Files AMass files High AMass files Output File Directory Begin Gain calculation L L Data file String Begin Output LL L J 1 Rebuild Log Fil x Enter data file directory d datal d datal Enter output file name i 5 Map iC NEED Data files Use on source frames off
141. am or the offset amounts The operation is the same for the MIRAC user as when using the RS232 command mode the offset files can be used etc and all the observing modes are supported Only nod and offset commands are available using the Ethernet control 74 MIRAC User s Manual 9 10 4 Offset Modes and Taking Data There are two possible offsetting modes Absolute and Increment The first mode means that the offsets values entered are the absolute displacement from the zero position If an image is taken at offset 0 0 and then at 3 2 the second image is shifted relative to the first If a third image is also taken at 3 2 it 1s aligned with the second image In the Increment mode offsets are entered in the telescope command menu that are executed every time a new set of images is begun Therefore if the offset increment is set to 1 5 2 the first image will have an offset of 1 5 2 the second image 3 4 etc relative to the starting position The increment mode is useful for scanning across a source with a constant step rate The offset value in the header for the increment mode will continue to show the total absolute offset relative to the zero position The absolute offsets can be entered in pixels or in arcsec The user enters one and the program calculates the other The values are stored in the file headers as pixel offsets since that is the information necessary to properly align the individual observations The tran
142. ample Mode is set to Dbl2Sampl the display can be selected to display the before and after reset on a single line as it appears on an oscilloscope or on separate lines so that the signal and reset levels can be clearly distinguished This is a very useful diagnostic mode for array performance When exiting the scope mode the camera parameters are automatically returned to the observe header parameters As a consequence if the I O program has not been initialized and or the camera is not operating the program will lock up and the MIRAC computer must be rebooted This can be prevented by executing OBS Init Simulate Data On 12 2 Temperature and Heater Monitor This utility provides for continuous real time display of the detector and thermistor temperatures as well as the current and heater power The sample interval can be chosen in 1 msec increments For each sample five A D reads are performed and averaged The detector and some of the thermistor temperatures are displayed on the default screen but this provides a way to monitor the situation more closely The heater power value is based on the calibration of the temperature monitor output and A D conversion assuming a heater resistor value of 25 12 3 Camera Control and Testing The commands in this menu allow the user to send various commands directly to the camera electronics Most of these commands are used during the normal operation of the camera to set operating parameters st
143. and Track command A RA Bias Rate B Dec Bias Rate Cx D urn Tracking ON urn Tracking OFF i Nod Beam Control 2 A Switch Nod Beam 0 B Change current MIRAC def C Beam 1 RS232 mode only D Beam 2 RS232 mode only E MIRAC Generated Nod Off F RA Nod Vector 0 G Dec Nod Vector 0 Tele OFFSET SO RS232 PLUSPULSI NEGPULSE EVEL ANUAL thernet KIRT RS232 p Offset control parameters 5 Command tel offsets On Offsetting Mode Absolute R A Offset Incr 0 00 Dec Offset Incr 0 00 Offset delay ms 3000 Anti Backlash offsets Off RA Abklsh sec RA 0 000 Dec Abklsh arcsec 0 00 Abklsh delay sec 0 00 Tel Offset com Guided offset 152 MIRAC User s Manual A12 2 DISP Command Line Menus DISP Init Load Header Begin Refres Clear Save OBS UTIL PRN Quit A12 2 1 DISP Init 1 of 1 of Display Array Stats and Fit Parameters gt Header Orientations Directions gt Log File Colors for Screen Display Array BLIP Calculation Parameters gt L Ji Magnified Display Width FWHM D
144. ar the end of the bundle Camera power cable to power supply Filter controller RS 232 cable to filter controller COM1 RS232 connector on PC Temperature monitor cable to A D Digital I O Interface Data Command fiber optic cable to fiber optic connectors at back of PC Red or orange are command blue or white are data Filter controller AC power cord to camera power supply switched AC outlet Cable Connections at Camera CAUTION At all times when the cryostat is not connected to the camera electronics the connector caps with conducting foam should be on the cryostat signal and clock connectors When these caps or cables are installed or removed care must be taken to keep hands in contact with the cryostat case to prevent static electricity discharge to the connectors Signal cable short length of 16 coax cables from electronics to cryostat signal output This is attached to the electronics preamp and stowed inside the top of the electronics box The small black ground shorting stub should always be in place on the branch of this cable The main connector on the cable must be disconnected from the test signal connector The shorting cap at the cryostat must be removed and stored in the cryostat assembly box The cable should be connected to the cryostat connector while maintaining hand contact with the cryostat to avoid static electricity sparks 192 MIRAC User s Manual Digital clock and bias cable from electronics to cryostat digit
145. art and stop integrations and resetting These commands proved useful while debugging the system One of the selections called continuous reset sends master reset commands to the camera as fast as it can until the user presses a key This was useful when debugging the serial transfer interface One could trace the progression of the data words through the interface giving the oscilloscope a fairly high trigger rate for easier viewing Also in this menu is an option to ignore images This option causes the PC not to process or save any of the data being taken Again this was useful when debugging the camera system because images were taken and sent from the camera at a much higher rate than if the PC was storing the data The Display Data option in this menu is a help when testing the signal processor boards This display shows the first couple columns of data in the SKY board buffer in hexadecimal format One can 5 22 99 12 Utilities 95 watch the buffers to see the image build up from many coadds while the integration is taking place From this display one can see if certain bits are not functioning etc The data is displayed in the same format as is directly sent from the camera So if the camera is in double sample mode there will be two values for every pixel for before and after reset 12 4 ASCII Output This utility provides a way to output some of the header and data information into a text file that can be later processed by ano
146. at on table right side up Window cover should be on window Close LN shutter Remove LN2 and LHe vent tube fittings Withdraw magnification LN shutter and pupil slide actuators Remove cryostat mounting plate with 5 32 allen wrench Put screws and spacers in large compartment in Cryostat disassembly plastic box If top support block has been removed for the IRTF reinstall it The block and screws are stored in the camera setup box Slightly loosen 8 5 8 inch 8 32 cryostat extension socket head screws with 9 64 inch allen wrench If the entire case is to be removed loosen the top screws as well Invert cryostat on table Remove 8 5 8 inch 8 32 socket head screws on cryostat base plate with 9 64 allen wrench Put screws in an empty compartment in Cryostat Disassembly plastic box For remaining disassembly each different sized screw should go in a different compartment Carefully remove motor assembly and set aside covering with a plastic bag Do not remove carrying straps from base of motor assembly O ring should be in groove on base plate Do not set any pieces on ring surfaces Remove 8 socket head screws holding cryostat case extension Remove extension being careful no to damage aluminum foil on inside surface and set aside on its side not on the 224 9 10 User s Manual O ring bearing surface Keep hands off inside surface Remove ring before is falls into the case The ring can b
147. ation file does the specified chop and or nod subtractions masking flat fielding and application of the gain map expands the map if desired and then writes the FITS image If the expansion factor chosen is a factor of 2 then the shift between array halves is properly taken into account All pixels that are bad or have no data in the gap between array halves are set to zero This alerts the data processing programs not to use these pixels when combining images for the final map The input files are in the standard naming convention 1 CYYDDMMA nnn where nnn is a number from 001 to 999 output files will have the same extension number as the input file so the eight character name should be different from the input The convention used is to make the new name the same as the old to retain the year and date information except for the first letter which is changed to an F to represent FITS file Also it is a good idea to specify a different directory for the files 96 MIRAC User s Manual to be written to so that the original data directory is not filled up and there is no chance of overwriting files When using this utility the images will be rotated so that the FITS file output has the proper orientation with N at the top and E at the left of the image This is done according to the current program settings of the N and E directions and the X and Y flips in the DISP Init menu For example if the N arrow is pointing up
148. center 6 5 6 5 6 5 6 5 6 5 6 5 6 5 6 5 00 MMTNULLS OFF for measuring focal plane scale at MMT nulling aperture with four points in corners of array 33 33 3 3 3 3 00 STD5 OFF for putting standard star in four quadrants and center of array 10 10 10 10 10 10 10 10 00 5 22 99 7 Observing Procedures and Check Lists 47 STDSKY7 OFF as above plus two off source sky positions for noise 0 50 0 50 10 10 10 10 10 10 10 10 00 SMALLS OFF for moving extended object a small distance on the array 22 22 5 2 5 2 5 2 5 2 00 TINYS OFF for very small dither for very extended object or slightly extended object in all four chop nod beams 11 11 5 1 5 1 5 1 5 1 00 JUP6 OFF 1 70 10 00 10 170 00 7 7 Focus Settings The telescope focus is optimized by having the telescope operator manually step the focus setting while monitoring the peak flux or FWHM ofa star Typical setting values are given in Table 7 3 Table 7 3 Focus Settings IRTF Focus Temp C Setting 2 07 2 07 S O 2 3 m 1 500 48 MIRAC User s Manual 7 8 Acquisition of Star and Focus Most telescopes reliably acquire stars so that the image should be in the MIRAC field typically 40 arcsec at IRTF However if the telescope configuration has been changed and the focus and initial pointing is uncertain acquisition of a star can be difficult For acquisition and focus MIRAC should be set as follows Obs Mode C
149. ck lists for shipping setup preparation observation data reduction and maintainance The asterisk indicates subjects most useful to review before an observing run Subject Chapters Appendices Organization of the manual and performance of MIRAC lt 2 Preparation for observing run mmc Al 5 Setting up and shutting down for a run and for a night of observing 55 546 Observing with the camera mes PP Vu A6 Quick look display and processing Toc 3 Post observing data reduction A7 A10 MIRAC files and menus All A12 Shipping and setup A13 15 Trouble shooting and service 16 A19 Unix commands tape backup weather and address information A20 24 5 23 99 Contents i Table of Contents List of Pigutes Xue ee es v cate cae vii List of Tables ponesi PE viii 1 Organization of MIRAC Users Manual 1 1 2 Overview and Performance esu qaom ed rdc R4 V E n Re ERE 3 2 1 MIRAC on the World Wide Web 3 2 2 General Description of 3 2 3 Magnification and Pixel Scales 522552515 ey bad Hb ER E ERAT 6 24 Filt r resistent ei ehe RO 7 2 5 16 Array and MIRAC System 7 2 6 Background Sensitivity and
150. cle with about 2 seconds of settling time required for each nod motion and to provide a reasonable sensitivity for an immediate display of a single observation For moderately bright sources gt 1 Jy arcsec at the SO 2 3 m or 500 mJy arcsec at the the integration time is just long enough to show a good signal to noise S N image of the source in a single observation One or two observations are taken at a sky position then the telescope is offset slightly for the next observation Typically 20 50 or more observations are taken for a faint source depending on the source flux and the desired signal to noise It is possible to freeze the motion due to seeing and chopper vibrations by using a short integration time equal to one chop half cycle In this case a poor duty cycle can be avoided by accumulating a large set 10 50 of chop image pairs in each nod position This can be done by using the MIRAC fast data mode If there is a bright enough source in the field the images be processed later by shift and add For an isolated source which is much smaller than the array field the signal to noise can be improved by a factor of two for any given observing time by putting the source in all four chop nod beams This is done by selecting chop and nod throws of about 20 arcsec so that the chopping and nodding causes the source to appear once in a different quadrant in each of the four beams Observations can be made with chop
151. coimages can be sent to the DSP at a rate of 56 Hz and 1 16 of the array at a rate of 800 Hz The camera controller generates the telescope secondary chopper motion and wait times synchronously with the read and frame times The coimaging and chopping can be intermittent stopping between observations or during nod waits or continuous The PC and array processor control the data acquisition storage processing and display and initiate telescope motions via Ethernet or RS232 The data can be stored both on the PC hard disk and on a facility computer disk via the Ethernet 5 23 99 2 Overview Performance AOLLON S3iMOlVHOBY QIAVYANI 30 AdVvisldd0ud ALNVUMOdRT NOISSINY3d A8 SI L33HS SIHL NO Q3NNINOO 1 0 30 385012510 80 ISN 35 an i IH La NEL M 8 BEES amp amp B a Sz _ 6 al 3 3 aal F 8 8 8 3 gt T O 8 X a N 3 lt Cis 9 NE REA S 234 2 o Q 9 35 p z Cc 28 S SEC ar E A SBD O ss gt 2N 2 AlN gt IN SST gt 58 c BU Se I amp 4TH BLOCK FILL PORTS IN LINE 6 PIN CONNECTOR 18 PIN CONNECTOR RIGID SUPPORTS NITROGEN VESSEL CASE HEAT EXCHANGER RIGID SUPPORTS COOLIN
152. cope collimation It is desirable to check this by observing out of focus images 5 3 End of Run Shutdown Tasks 5 3 1 Initial Control Room End of Run Tasks 1 Complete nightly shutdown tasks Section 6 2 2 Photocopy any MIRAC log sheets not already copied for the observers Gather all the original log sheets including cryogenics log and worksheets from the MIRAC log clip board and or the three ring binder marked MIRAC Current Log and mail to Bill Hoffmann for the MIRAC archive 3 Mail DAT backup tapes for the run to Bill Hoffmann for the MIRAC archive 4 Pickup and organize the MIRAC work table 5 Shut off PC power when backup tape is complete 5 3 2 Telescope Chamber End of Run Tasks 1 Collect from the control room on or next to the MIRAC power supply 1 Camera Assembly plastic box with Two MS connector shorting caps Fiber optic end protecting tips 5 22 99 5 Start and End of Run Setup and Shutdown Check Lists 21 Miscellaneous tools 2 Gray foam cable end protector marked Camera containing the Green Elco cable end connector male with pins shorted together 4 MIRAC velcro cable straps mounting board 5 Round plastic container with short pieces of blue nylon string 6 Two round and one rectangular cover plate for guider box openings If the guider box is to be removed 7 Guider Box Assembly plastic box with Tools and screws for guider box installation Removal of Cables 2 At the telescope remove the tw
153. ction If the selection alters a parameter the current value of the parameter is displayed If the selection executes a function there will be a blank space on the right side of the menu across from that item Again there are a number of ways to choose a selection One way is to use the up and down arrow keys to move the highlight bar to the desired position and then choose by pressing ENTER or the PageDown key Another way is to type the first letter of the selection However if there are more than one selection with the same first letter the first one on the list is always chosen 5 22 99 9 Using MIRAC Program 65 OBS Init Mode Header DESS Run Wait Save Tele DISP UTIL PRN Quit Obs Mode Chop Log S av OnOff Off RA 0 00 Chop lt gt 10 90 AMBT emp 9 53 Off Dec 0 00 FrT imet ms gt 19 661 EleTennp 22 68 Fitter 1 11 7 pm Burst Mode ON A DT emp 44 84 Filtr 2 Open IntTimecs gt 0 98 DetTemp 5 005 Wavelth 11 70 RAUG 3 063 5 gt Next Observation hObject Simulated Star Wave leng DO 4 Integration time 0 983 Frame Time Cms 19 6608 j Chop Nod Mode Chop G Save all observations Off How many Obs per run 16 Read offset file Use command file Link Frame Filter sky frm z Macros 7005 Shell current position o Section Full Map Data gt Max 3 40 lt 64 64 gt Dnin 1 40 113 16 gt Fit gt 3 40 63 96_63 97 FWHM 3 08 5 0 002 Total RMS
154. d in the OBS Mode menu of the MIRAC program The first choice that must be made is whether to use the secondary chopper The CHOP mode must be selected if the chopper is to be used The GRAB mode is defined as taking an unchopped image second choice that must be made is whether to send NOD commands to the telescope This command causes the telescope to offset to some predefined off source position There are two nod options a two beam nod and a four beam nod which are used with and without the chopper When an Observation is saved to the disk file all off source images in the set saved to the same file Then when an image is read from disk and displayed the off source images are properly subtracted to show the source The data taking options are described below 9 9 1 1 Grab This mode takes a single image with no telescope motion This is selected by setting the Grab Chop switch to GRAB and setting the nod mode to OFF This mode is usually used during an observing run to take data to be used in calculating the gain map 9 9 1 2 Chop This mode runs the secondary chopper and stores 2 images to the data file one for each chopper beam This mode is selected by setting the Grab Chop switch to CHOP and setting the nod mode to OFF The On Source beam can be selected in the OBS Header Observing Parameters menu as either 0 or 1 corresponding to the 0 or 5V logic level output of the chopper bit from the interface box This designa
155. dard Error and Output gt amp Standard Error Separately command gt output gt amp errorfile Pipes Pipelines command filer filter Duplicating Displayed Output command tee filename Filters Word Line Count we 1 A20 VMS DOS UNIX Command Reference 231 First n Lines head n Last n Lines tail n Skip to Linen tail n Show Nonprinting Characters cat v Sort lines sort n Format Paragraphs fmt Reverse Character Order rev Multicolumn Output pr t List Spelling Errors spell Substitutions in Output Stream sed e s pattern string g Report Generation awk 2 3 Searching with grep grep Command grep pattern filename command grep pattern grep Search Patterns beginning of line end of line any single character single character in list or range character not in list or range Zero or more of preceding character or pattern zero or more of any character escapes special meaning 3 C Shell Features 3 1 History Substitution The History List Set Up History List set history n See History List history h Event Designators Repeat Previous Command 232 User s Manual Display Previous Command Ip Command Line n In n Commands Back l n Command Beginning with str Istr Command Containing str str All Arguments to Prev Command Last Argument to Prev Command I First Argument to Prev Command Ls n th Argument Word Designators
156. data This allows the user to sort out images for which the source is off the array the sky noise or background level has changed or there are any other problems with the image Depending on the options set in the DISP Init menu the statistics and fit will be displayed The header information from the image file is displayed on the screen where the observing header is usually displayed This is the only function in which the previous data header is displayed here After the Replay function is complete the header display reverts immediately back to the current observing header There are a number of options in this mode First a range of images can be entered in the usual shorthand notation The entire chopped nodded etc image can be displayed or a single frame from the set can be selected Any gain mask or flat field that is active will be applied to the data Finally a pause between each image can be turned on or off In any case the mode may be interrupted at any time by typing Q to quit After the mode finishes the last image displayed is left in the image display buffer 11 1 4 Operation This mode has the capability of loading individual files or performing simple math operations with raw data files When doing operations with observation files they must all be the same size The Operation calculation is done without any offsets If they are active the gain or flat field operations are performed on each individual file as it is
157. description of the design and performance of MIRACI and can be found in the articles MIRAC a Mid Infrared Camera for Astronomy W F Hoffmann G G Fazio K Shivanandan J L Hora and L K Deutsch Proc SPIE Infrared Detectors and Instrumentation 1946 449 1993 and 2 a mid infrared array camera for astronomy W Hoffmann J L Hora G G Fazio L K Deutsch and A Dayal Proc SPIE Infrared Astronomical Instrumentation 3354 647 1998 MIRAC3 is Mid InfraRed Array Camera built for ground based astronomy at Steward Observatory University of Arizona and Harvard Smithsonian Center for Astrophysics It utilizes a Rockwell HF 16 128x128 arsenic doped silicon blocked impurity band hybrid array operating in a liquid helium cooled cryostat at 5 It has an operating wavelength range of 2 to 26 um The relative quantum efficiency over this range is given in Figure 2 1 Using 16 parallel readout lines giving a frame rate up to 92 kHz the array provides both low noise and good linearity at high background flux which are essential for 10 and 20 micron ground based observing conditions The array has a peak quantum efficiency of approximately 0 42 at 22 um and full well and linear well sizes of 2 4x10 and 1 6x10 electrons The quantum efficiencies at 2 2 5 and 11 7 um are approximately 05 25 and 36 4 MIRAC User s Manual Figure 2 1 Relative spectral quantum efficiency of the Boeing Si As BIB
158. directory e g D D941209 All observations from current session e g C921209A 001 Processed observations Files that should be in the SSAO directory The Smithsonian Star Catalog Files that should be in the UNIX directory AIRCOR TARWRITE AIRMASS AIRCOR C DEALLOCA AIRMASS C MRC2FTS FITSIO C OBSLIST MRC2FTS C TARLIST OBSLIST C TARREAD FIOCOM H 5 22 99 12 1 OBS Command Line Menus 145 Appendix 12 Command Line Menus A12 1 OBS Command Line Menus OBS Init Mode Header Next Run Wait Save Tele DISP UTIL PRN Quit A12 1 1 OBS Init F Observe INIT Camera Init I O Init DSP board Log Options Data File Dir Backup data Dir Name of DSP Program Simulate Data MIRAC Settings File Program Values Le d Nd941209 i Nd941209 c mirac mirac dsp CURRENT HDR gt Simulate Data File for SimSource Use Source file Load SimSource File Normalization factor Width FWHM of source 3 000 Off jupiter chp Off 2 000 L Record Log Log File 12 09 94 LOG Scan Log file Insert current Header J Telescope COM port Baud Rate Tel COM Parity Tel COM Stop Bits Tel COM Word length Tel Alt Tel com file RS232 CHKSUM mode Min Chop Wait cycles rogram Values Filter Control COM port TCS command confirm mode Of
159. dius is too small no stars will be found for that object SAO stars will not be found for STD SAO or BST object types The star coordinates are accurate to about one arcsec and the proper motions to 1 arcsec century Some examples follow obslist sources cat a 14 23 34 3 23 12 11 02 0 23 1 12 STD 1950 0 STAR1 s the above star is added to the end of the list then the list is sorted and the output catalog sent to sources cat overwriting the old file obslist sources cat a s p t sourceT cat gt sources lst the sources cat file is read in then the program goes into interactive add source mode to allow the user to type in a number of objects then sorts the objects makes a file SOURCET CAT for use on the telescope and prints a listing of the sources The listing has been redirected to the file SOURCES LST OBSLIST was written in C for a PC but can just as easily be run on other systems such as Sun computers To compile the program on a PC using Microsoft C compiler vers 5 1 use the following statement cpl F 9000 obslist c On a Sun use the following command cc obslist c lm o obslist The size of the arrays set in the program below can be changed to increase the number of sources allowed using the parameter MAXSRC in the program In the case of the PC the stack size may also have to be increased the F parameter above For other systems some tweaking may be necessary but the program uses fairly standard C so it
160. dow orientation Secure with the three Velcro straps 33 Place the plastic bag over the cryostat 34 Lay the cryostat into the foam cradle in the crate orientated according to the markings on the foam It is a snug fit and requires some adjustment of the foam Check that the short length of vacuum hose is in place Insert the top foam piece and close the crate 30 MIRAC User s Manual Packing the Guider Box 35 If the guider box is to be packed it goes in MIRAC Crate 1 Follow the instructions in the Shipping Inventory A13 4 5 4 Complete Shut Down and Packing If MIRAC is to be packed for storage or shipping disconnect all cables in the control room the power connector last installing optical fiber protectors and the cable end sheath as at the camera end The fiber optics couplers belong to MIRAC and should be placed in the Computer Setup box Remove cable bundle from its supports in the telescope chamber returning all velcro straps to the MIRAC velcro cable straps board Carefully thread the cable from the control room into the telescope chamber Return the cable to its crate in reverse of the setup instructions Section A14 6 Pack MIRAC according to the shipping inventory Section A13 4 If MIRAC is to be shipped follow the instructions in Section A13 1 5 22 99 6 Nightly Startup and Shutdown Check Lists 31 6 Nightly Startup and Shutdown Check Lists The convention for indicating MIRAC program commands in this and subsequen
161. e and then the observation 15 started The entered offsets stored in the observation file header and written to the observing log Note that for the calculation of offsets and airmasses to be correct the proper Right Ascension and Declination for the source must be entered in the header The user usually wants to specify small offsets in arcsec whereas the telescope requires R A offsets in seconds of time so the proper coordinates must be entered in the OBS Header Source Information menu in order for the program to be able to convert from arcsec to hour angle 5 22 99 10 Mask Gain and Flat Field Maps 75 10 Mask Flat Field Maps 10 1 Mask Map The mask map specifies which pixels are to be used in statistics calculations fitting mosaic construction and many program operations For display and some operations the masked pixels are set to the value zero When new data is being saved the mask is applied only after data has been saved in its original form Therefore pixels that are masked during data taking can be later restored simply by turning off or changing the mask DISP Load Auto Mask Edit contains a number of ways to enter and edit the mask First pixels can be set by using the mask editor in Edit The editor displays the array pixels on the screen with the current masked pixels displayed as blocks and unmasked pixels as dots The cursor can be moved around the mask with the arrow keys Typing S caus
162. e images have been combined All points within the boundaries of the image where no data has been coadded are set to zero 82 MIRAC User s Manual 11 1 6 Multiple Image Display It is sometimes convenient to display multiple images to compare different data different processing or different gray scale limits A display of any number partial images can be constructed as long as the total array size is 256x256 pixels or less method uses DISP Header Source Information Image coordinate parameters UTIL Arith Justify map and UTIL Arith X flip Y flip It is helpful for determining the desired portion of the image to set the display grid spacing to 10 pixels line This can be done by setting the pixel scale to an integral lOths of an arcsec OBS Header Filters and Optics Arcsec Pixel and the grid spacing to 10 x arcsec pix DISP Init Arcsec grid display Arcsec Grid Lines On Grid Spacing arcsec 10 x arcsec pixel The initial images should be scaled so that the same grayscale display limits are optimum for all of them Addition and subtraction of constants must be carried out before generating the partial images The following example displays in four quadrants four partial images with filenames filel file2 file3 and file4 partial images partiall partial2 etc and combined image combine A 63x63 pixel portion of each image is used to allow a 2 pixel wide gap between images For this example the first 50 and last 15 columns and firs
163. e Off 17 Carry out Nightly Startup Task 10 18 Check Printer settings PRN Init Printers Chose Printers PS File psout nnn Postscript Printer Current Page 1 Print Option Gray Map NOTE The printer selection Network PS LPT2 can be chosen but it is slow It is more satisfactory to print to a file which is saved in the observing directory and print the files to the network when it is convenient 19 Carry out Nightly Startup Tasks 11 26 MIRAC User s Manual 20 Preparation for Initial Camera Power up For the first power on at the site confirm that the cables are connected correctly Section A14 6 At the beginning of a run it is best to run the camera without the cryostat using the test signal If this is to be done make sure that the preamp signal cable is connected to the test signal connector at the top of the camera electronics Running without the cryostat is described in Section 16 5 If the camera is to be run with the cryostat and detector make sure that the signal and digital cables are connected at the cryostat The first power up of a run is a good time to check the power supply voltages and currents as marked on the power supply and described in Appendix 18 21 Carry out Nightly Startup Tasks 12 18 22 Note Nightly Startup Tasks 19 21 23 Dichroic alignment This is required to make sure that the camera is coaligned with the telescope The procedure is described in Section A14 11 24 Teles
164. e detector reset during non destructive reads 5 22 99 16 Checking and Trouble Shooting 209 Figure 16 4 HF 16 multiplexer format Conversions between channel line number L and block number B and column C and row R are given by Int L 1 2 8 Mod B 1 16 1 Mod L 1 2 2 Int B 1 16 1 oe 17 07 usec SOn FASTCLOCK Manuinn LINE SYNC 2400 B Int 1 8 16 Int C 1 2 1 ENG FSYNC goes low 2 FSTCLK cycles after LSYNC L 2 Mod R 1 8 Mod C 1 2 1 0 8 16 24 32 Fast Clock Cycles A16 8 Camera Timing The HF 16 requires three standard clocks and one non standard for burst mode standard A 10 5 HF 16 clock timing clocks are fast clock FSTCLK which advances 210 User s Manual the array readout one block each transition line Sync LSYNC which advances the readout two columns 16 blocks each transition and frame sync FSYNC which sets the shift registers at the beginning of the read cycle and controls the reset timing These are shown in 16 5 The readout advances one block of 16 pixels with each transition of Fast Clock Each transition of Line Sync advances the readout two columns Frame Sync resets the shift registers to the first block Each of the clocks runs between a low of 4 0 V logical 0 and high of 9 0 V logical 1 In MIRAC2 the rise and fall times of the clocks are
165. e in FITS format r nl n2 process a range of images starting with number n1 and ending with n2 In this case the file name given to the program should be the root name or everything up the file extension n do not rotate the data to the normal orientation N up and E to the left The default does rotate and or transpose the data if necessary This n option is necessary when processing the data for the gain or mask maps since these are applied to the data before rotating or transposing i do the column interchange necessary for all data taken between June 1994 and October 1994 This is required for all the Jupiter Shoemaker Levy 9 collision data but not for any data taken after October 1994 when the hardware swap was corrected d outdir use the data directory outdir as the place to write the output files to This allows the user to write the files to a different directory than where the raw data is located f the input files are in FITS format not the default MIRAC3 format o n instead of reading all the frames and combining them in the usual way only read frame n in the set and write that to the output file and add a n to the end of the output file name e g f941224a 001 3 p the input data files are packed In this case the only other option valid is the r range option The program unpacks the files and writes them to FITS files The mrc2fts program must be then run again with the f option to expand appl
166. e left on OBS Init Log The number of observations in a run is given in OBS Mode How many 9 8 Filter Wheel Initialization and Motion The MIRAC program handles the positioning and control of the filter wheels via an RS 232 link to the motor controller located at the camera electronics The program keeps track of the current position of the wheels writing to the file MIRAC FIL every time the wheels are moved This file is located in the same directory as the executable program file MIRAC EXE MIRAC FIL also contains the magnification setting The various commands to initialize and move the filter wheels and set the magnification are located in the OBS Header Filter and OBS Header Optics menus The filters must be initialized with OBS Header Filters Init Filters to insure that the wheels are in the correct position This should be done when the power is turned on at the beginning of the observing night whenever the camera has not been operated for a long time or whenever there is any doubt as to the current position of the filters The Init Filters command sends a HOME command to the controller which places both wheels in the position defined by the limit switches as home or position 1 All other positions are relative to this initial position Occasionally the program will issue a HOME command during the normal course of operating the filters to help insure that the position of the wheels is accurate The switches on the filter controll
167. e lifted from the grove with a Q tip broken to form a tapered sharp end Cover both with plastic Install the large cardboard MIRAC cryostat assembly skirt at the LN radiation shield case interface in order to prevent screws from falling into the cryostat The skirt is located in the MIRAC Working Files Cryostat Assembly folder Remove 3 16 inch 4 40 screws holding LN radiation shield using screwdriver and tweezers The Craftsman 1 8 inch screwdriver is best for loosening the screws and the large blade jeweler s screwdriver and fine tipped tweezers best for removing them See Reassembling Cryostat Section A19 7 for instructions for removing LN radiation shield bottom Using gloves gently rock and pull radiation shield to loosen it It might be necessary to pris the shield on the right and left sides with a screwdrive and penny or nut as a fulcrum Remove it and set the shield aside The three filter wheel drive rods will be attached Install the smaller cardboard MIRAC cryostat assembly skirt at the LN radiation shield LHe shield interface Remove the circle of slotted 3 16 inch 4 40 screws at the base of the LHe radiation cover Remove the circle of slotted 1 8 inch 2 56 screws 1 2 way up LHe radiation cover Remove LHe shield using gloves and gently rocking and pulling A19 2 Removing the optics and filter wheel assembly 1 2 3 4 5 6 7 Put on grounded wrist cuff Using Scotch Magic tape lightly tape the s
168. e not suitable for photometric calibration but still are useful such as IRC 10216 the brightest non solar system mid IR source and Mu Cep The tables give the magnitudes ordered by right ascension and both magnitudes and flux density in alphabetical order Bright mid infrared sources are generally cool stars with complex broad atmospheric absorption features which make the magnitude at a given wavelength dependent on the band width They often have dust envelops which provide additional emission or absorption bands and make many of them non point source objects Also many of them are variable The notes in Section A2 2 give some details about these problems The entries in the table marked MIRAC are taken from selected sources Gezari Schmitz Pitts and Mead Catalog of Infrared Observations Third Edition NASA Reference Publication 1294 June 1993 Those marked Cohen come from Cohen Whitteborn Walker Bregman and Wooden AJ 110 275 1995 Those marked Hanner are from a private communication from Martha Hanner May 25 1994 The conversion from magnitude to Janskys is taken from Cohen Walker Barlow and Deacon AJ 104 1650 1992 This is based on taking the magnitude for Alpha Lyra to be zero at all wavelengths It fits closely by an 11000 K black body with corrections for individual wavelengths which range from 0 017 to 0 016 magnitudes The zero magnitude flux density can be obtained from the values for Alpha Lyra in Tab
169. e the Ethernet ports are located just above the PC in a silver strip mounted on the wall The TCS RS 232 ports are two 25 pin D sub connectors in a breakout box mounted on the wall The chopper control box is usually placed on the shelf above the Sun workstation MIRAC printing is done by transferring Postscript files via Ethernet to the observatory Postscript printer At the IRTF the MIRAC system should be located on a long table placed against the telescope computer room wall facing east The telescope and focal plane monitors mount paddle focus paddle and intercom microphone should be on this table along with adequate space for observing log books and notes The PC Computer connector positions are given in and Figure A14 4 MONITOR 9 SEES O A D DIGITAL 1 0 POWER SUPPLY 2252 A KEYBOARD 20 Inches Figure 14 3 MIRAC Control Room Layout 5 22 99 14 Hardware Preparation and Setup 185 lt 8 375 gt uc ON OFF SWITCH PWOER KEYBOARD C MOUSE FILTER PRINTER COM TELESCOPE 18 25 DATA COMMANDFIBERS n oa mee cHoPPER BNC C ETHERNET AJD DIGITAL vo Figure 414 4 MIRAC PC Connector Positions 14 5 Camera Installation at Telescope Tools and screws for mounting the guider box are in the Guider Box Assembly plas
170. e transferred via the Ethernet to the telescope computer At the SO 2 3 m the source files should be placed on a 1 44 MB 3 5 inch PC floppy The MIRAC program uses the source lists to automatically load the R A and Dec of an object into the header This is done in the OBS Header Source Information menu using List of Sources and Find Source commands For the observing run all of the sources of interest should be entered along with 2 or 3 SAO catalog stars as close as possible to these objects The OBSLIST program can be used to locate the nearest SAO stars to the sources The SAO stars should also be fairly bright mag 7 0 or less to be easily located Occasionally there is a problem with an SAO star wrong coordinate proper motion etc 50 it is a good idea to have three or more Also can offset between SAO stars to test pointing and offsetting near the source IR calibration standards should be entered in the same list at coordinates throughout the sky so that at least one will be observable at all times AIRMASS uses CAT files to create tables that show airmass versus time of night of the sources for the date of interest 4 2 Offset and Command Files Command and offset files should be prepared in advance These are described in Sections 7 5 and 7 6 20 MIRAC User s Manual 4 3 Establishing an Individual Guest Account At the IRTF guest accounts may be established 3 days before the start of an observing run and expire 3 da
171. eam Setup Each Night 25 hr Recheck IR focus Observation Sequence 15 Record pictures of a calibration star at wavelength of next source observation Typically 12 5 second on source integrations in chop nod mode with a sequence of 12 50 MIRAC User s Manual offsets or paired with a sequence of 6 offsets If extinction data is desired this should be done at other wavelengths for the nights observing as well with resulting additional time 1 hr Record pictures of object at selected wavelength Typically 24 20 second on source integrations in chop nod mode grouped in sets of 12 paired in a sequence of 6 offsets The telescope drift is checked between each set 15 hr Repeat calibration star Gain Map Determination 25 hr Record pictures in grab mode of the sky at 1 and 2 airmass at each wavelength of the nights observations This is typically 10 5 second integrations for each wavelength at 1 airmass and the same for 2 airmass 7 13 Calculating Image Scale The image scale can be determined from standard star images such as obtained by the method given in Section 7 9 Load the images with DISP Load Mode Operation Load Directory filename lt enter gt lt enter gt Determine the column and row fit positions from the image display statistics Select the desired quadrant with DISP Init Stat and Fit Region for Stats For the quadrants with the negative source image invert the image with UTIL Arith Multiply lt ente
172. ectly from the sky board so it must be properly sorted and put into the MIRAC file format To run the utility the input files and output directory must be specified fast data file names the same format as the normal data files except they begin with a P for packed instead of the usual C Each file within the packed file has its own unique file number so when the images are written to individual files they are given the file name with their number in the usual naming convention The output files are all given a copy of the header of the original packed file with a sequence number to indicate their position within the packed file 5 22 99 12 Utilities 97 12 8 Rebuild Log File This function provides a means for creating a log file from a set of observations 12 9 Arrange data into lines or image This switches between the array image format of 128 x 128 pixels and the array readout format for which each array readout channel of 1024 pixels is displayed as eight columns 12 10 Exchange columns to fix image This is a feature to correct a column exchange problem in the data from August 1994 12 11 Standard Deviation calculation This utility calculates a standard deviation value for each pixel from a number of separate observations This is useful in identifying high noise or other bad pixels The most common data input would be chop chop nod or nod only data One can select to use only the off source chop in a chop nod
173. elow the camera electronics 9 Disconnect the Power connector at the electronics panel This should be the last cable disconnected Put the green male ELCO connector on the cable end connector to protect the pins 10 Open the gray foam cable end protector and carefully insert the power connector RS232 connector MS Temperature Monitor connector and end of AC cord and re close the protector with the velcro strip 28 MIRAC User s Manual 11 Detach the cable bundle from the three velcro straps at the top of the electronics Secure the cable bundle end together with a beige velco strap Remove the cable bundle from the MIM If MIRAC is to be left setup at the telescope relocate the cables onto the yoke using the velcro straps or blue string Make sure that any unused velcro straps are returned to the MIRAC setup in the control room 12 If the on axis camera has been used disconnect the power and video connectors from the camera 13 Return the screwdriver to the Camera Assembly box Return the box of string Filter Controller Power cable Digital cable and extra velcro straps to MIRAC table in the control room Removal of Electronics Box and Cryostat 14 With an allen wrench remove the two socket head screws in the brass bracket at the top of the camera electronics Reaching in from the bottom of the electronics loosen the two captive knurled knob screws at the base of the electronics Lift the electronics off the cryostat bracket and pl
174. em programer Tony Denault denault galileo ifa hawaii edu extend this account to the full MIRAC run plus a few days It is necessary to edit the IRTFDRIV BAT file in c nfs for the user name and password before executing NETIRTF The MIRAC PC should mount herschel scrs1 mirac as the 1 drive A second directory can be established as the j drive The backup drives should then be i or j These be accessed from any IRTF computer as scrs1 mirac If it is necessary to change other network parameters the files c nfs irtfnet bat and irtfdriv bat should be edited keeping the old lines sit rem at the start of the line and then reboot with netirtf from the DOS prompt network numbers for MIRAC are miracpc 128 171 165 60 gateway 128 171 165 62 DNS 128 171 165 1 128 171 1 1 Subnet mask 255 255 255 0 NIS Server 128 171 165 1 disks herschel scrs 1 mirac aux1 home mirac printer irtfpr At UKIRT on kiki export ukirtdata mirac data At the Steward Observatory MIRAC lab Set the MIRAC PC date and time When the PC is turned on or booted its clock is automatically set from the network to local time in the MIRAC lab and to UT at each observatory The time is automatically reset from the network each time MIRAC is run The time can be reset manually at any time For the PCNFS network software Steward Observatory and IRTF execute the batch file TIMES or RDATE host where host is the name of the observato
175. emperature Sensor Calibration Temp Resistance Resistance Resistance Resistance Kelvin Kohms Kohms Kohms 1 Kohms 3 9 8 7325 ELA 22 19 34 13 9 35 13 7 ren ES ren Hn 1 12 65 i ES dE TDI ds Oo D 5 22 99 17 Cryostat Inputs and Outputs Table A17 7 Clock Inputs 5 24 Dig V J2 20 64 VDDR 9 9 9 4 Notes Clock rise and fall times should not exceed 10 nsec Table A17 8 Filter Wheel Switches Wheel 2 1 Sw A Common Home 2 Sw B N C 2 9 220 MIRAC User s Manual Table A17 9 Temperature Control Cryo In line Name Wire Circuit Conn Ohms Ohms Temp A LHe Diode return Temp B LHe Diode sense E Diode Temp C LHe Diode sense 68 Temp D He Diode current 33 6 Temp E 2 Diode current Temp F LN2 Diode sense E Diode Temp G LN2 Diode sense 74 Temp H LN2 Diode return 1 2 Heater Temp L 1 1 Heater Gnd HE Ds ES Et N HH cen Table A17 10 Preamp Offsets Voltage Input Shift Digital Shift Low Offset 8 26 4 13 13530 Medium Offset 7 16 3 58 11730 High Offset 5 51 2 75 9020 Variable offset 2 61 92 3 46 11330 Table A17 11 Digital and Signal Ground Shorting Connectors Digital Shorting Connector Bias reference Dewar shield case
176. er at the camera should be remote off ground off The filter controller power is turned on by the PC only for the duration of a filter command sequence during which time a red LED light is on at the filter controller As each individual motor is powered prior to moving a small click can be heard and the motor holding detent becomes very strong Filter settings can be made from the OBS Next Wavelength menu or from the OBS Header Filters menu After confirmation that a filter change is wanted the command is sent to the filter wheel controller The computer will pause momentarily until the command is carried out Note that this menu is different from others the program in that you cannot cancel changes by hitting the Alt F1 key Once a wheel has been moved it must be commanded back if one desires to restore it to its original position To move to a position on the CVF the BaF blocker must be used in filter wheel 2 This is done automatically in the Next menu 9 9 Observing Modes and Options 68 MIRAC User s Manual The MIRAC program is flexible in the different ways it can take data Appendix 1 contains discussion of mid infrared observing The high background of the sky and telescope must be removed by taking reference frames along with images including the source This is done by various combinations of chopper motion and nodding the telescope 9 9 1 Source Frames and Off source Beam Switch Options The observing mode is selecte
177. erature setting for servo control of the detector stage temperature The normal settings are Remote Auto 194 MIRAC User s Manual There is also a temperature sensing resistor on the detector chip carrier which is accessible at two tinned wires inside the electronics enclosure The temperature resistance values are given in Table A17 6 A14 8 Setting the LN Shield shutter Pupil Stop and Magnification The LN shutter pupil stop and magnification must be manually set at the cryostat The settings for the latter two should be entered into the header These parameters are entered in OBS Header Filters and Optics The LN actuator is located just below the cryostat window It is engaged by inserting the actuator rotating it to find the slot on the mating piece inserting it into the slot and rotating it to capture the pin The shutter can then be withdrawn until it stops and the actuator rotated to disengage the pin and fully withdrawn The pupil stop has six positions as given in Table A14 4 The pupil actuator is the one furthest from the vacuum valve The actuator must be inserted and rotated until the pin engages a slot At that point there should be no space between the knurled knob and the bottom plate of the cryostat The only way to be certain of the pupil setting 15 to run the camera in grab or scope mode and rotate the actuator fully clockwise looking up towards bottom of the dewar to the blank position confirming this with the b
178. es the pixels at the present and subsequent positions of the cursor to be set C to be cleared and M to be unaffected Move E exits the mask editor Pixels can also be masked if they are above or below a user specified threshold value for an image which has been loaded through current operation or replay This is useful if high dark current or unresponsive pixels are to be masked The mask should have been turned off in DISP Load Auto before loading the image The mask should be cleared in MaskEdit Then the threshold criteria can be used to eliminate pixels It is helpful to first display the array data as a histogram to determine what the lower and upper thresholds should be used A reasonable sequence creating a mask follows It is generally satisfactory to just use the first step 1 Mask high pixels Using a blanked image grab at a standard frame time displayed with mask gain and flat off clear mask and cutoff the high dark current pixels the 10 16 highest 2 Mask low pixels Using the difference between a flat image at a moderately high flux level grab or off source frame of a chop nod observation and a blanked or low flux flat image with mask on using the mask created in step 1 disregard low pixels those less than 6 of the median This will mask vignetted as well as unresponsive detector pixels 3 Mask high noise pixels Using UTIL Function Calculate STD Dev image and a series of off source chop n
179. ffsets The main display can then be made to match the TV guider and show the observer the orientation of the array However the data is always stored in the disk files in the same way and displayed in the following display modes in the same way So for example if the Y flip mode is on the default display will be upside down compared to the Contour mode described below in Section 11 2 2 Any data in the image display buffer can be manually flipped using the UTIL ARITH flip options to give the image the proper orientation Of course then it would appear properly in Contour and flipped in the main display screen 84 MIRAC User s Manual 11 2 1 Grayscale This mode displays a full screen grayscale image of the full image display buffer This allows images larger than the 128x128 array to be displayed The screen pixel size is adjusted to make the image as large as possible without overflowing the screen This mode is shown in Figure 11 1 Options Setup Redraw PETH Exit 128 112 64 48 32 16 lt 64 64 16 32 48 64 96 112 71 1364 MIRAC2 U of Arizona Smithsonian Ast Obs OBS 4 05 96 15 08 21 c960405a 001 SIMULATED STAR IDLE 0 00 0 02 0 50 DISP 4 05 96 15 05 40 81 Data not saved SIMULATED STAR Mode Current Figure 11 1 Grayscale Display Mode The parameters which control how the grayscale plot is displayed can be changed using the Setup command once the plot has been displayed They may also be changed before
180. filename 2 4 Print File Type Ipr filename inquire printer status enscript G filename page w header 2 5 List Files and Directories Type Is for listing of current directory ls a list all files Is 1 list all details 15 directory name for listing of another directory Is filename for listing of a single file 15 t or ls t filename or ls tdirectory name to get a listing reverse sorted by time of last modification ls F or ls F directory name to get a listing that marks directory names by apending a character to them 2 6 Move or Rename Files and Directories Type mv source filename distination filename to rename a file mv source filename destination directory to move a file into another directory mv source directory name destination directory name to rename a directory or move it into another directory 2 7 Files source filename destination filename to copy a file into another filename cp source filename destination directory to copy a file into another directory 2 8 Remove or Delete File Type rm filename to remove a file rmdir directory name to remove an empty directory rm r directory name toremovea directory and its contents 2 9 Change Working Directory Type cd to change directories to your home directory cd directory name to change directories to another directory 2 10 Find Name of Current Directory Type pwd 2 11 Pathname
181. g order Read in specified file Add sources if selected Delete sources if selected Sort sources if selected Output file if sources have been altered by above Output telescope file Print listing The format for the Steward Observatory telescopes catalog file is as follows with no space between items record number nnnn visual magnitude 100 mmmm RA in radian I rrrfrrrfrr Dec in radian RA arcsec 100000 yrs Dec arcsec 10000 yrs Label Field text 64 chars Epoch 1950 assumed eeee ee CR LF ec The format for the IRTF catalog file is name RA DEC RAProperMotion DecProperMotion Epoch where name up to 40 characters spaces this program fills spaces with RA hh mm ss ss DEC dd mm ss s RA PM a aaa Seconds Year DEC PM a aaa arcsec Year Epoch yyyy y The format for the UKIRT catalog file is No of lines object Object name RA DEC Epoch Column numbers are important 12345678901234567890123456789012345678901234567890123456789 LKHA1 98 00 08 47 000 2458 33 06 01 B1950 0 NGC1068 02 40 07 201 00 13 30 00 B1950 0 122 MIRAC User s Manual The files for the SAO star search switch f are ssao 00 ssao 42 provided by picoscience for use with their Superstar program When the f option is used the program searches through the proper ra ordered file for objects within a certain radius of the target If the ra
182. gt imlist l peakl eval imlist 30 utput peak coordinate file is pk200 1 On 22 304 rame 4200 Center cursor on peak press spacebar 1 0 22 30 rame 201 Center cursor on peak press spacebar 12 Ox 22 30 l gt xlist pk200 pkx200 gt xcor 921210a 212 p pkx200 sr sw atauoffs ross correlation program xcor c ow reading reference imag ile 921210a 212 header read parameters 130 84 ow scaling reference imag 4 130 84 eference peak found 307639 at 63 31 ile 921210a 200 header read parameters 130 84 ow rescaling search image 4 130 84 Peak used is 374406 at 77 79 Window corner at 67 65 Results ZLS 46 0 98957 0 37879 0 67805 32 32 ile 921210 201 header read parameters 130 84 ow rescaling search image 4 130 84 Peak used is 377523 at 81 67 Window corner at 71 57 Results 20 36 0 99232 0 36268 0 68268 32 1 gt type pk200 921210a 200 76 481 77 969 101 040 921210a 201 81 530 67 871 101 040 l type atauoffs 921210a 200 78 77 130 84 15 46 0 98957 0 37879 0 67805 921210a 201 83 67 130 84 20 36 0 99232 0 36268 0 68268 1 gt makelist atauoffs atauoff2 1 gt type atauoff2 921210a 200 78 77 130 84 921210a 201 83 67 130 84 139 225 226 227 28 29 23 0 32 533 34 140 MIRAC User s Manual cl lcoadproc atauoff2 ataull7 35 Warning Cannot access image tempbigl Warning Cannot access im
183. gure 14 5 MIRAC Camera Mounted on Telescope 186 Figure Al4 6 Camera Electronics Connector Positions 187 Figure 14 7 IRTF Cable Routing at the telescope 189 Figure 14 8 IRTF Cable Routing to Control Room 190 Figure 16 1 MIRAC Main Screen showing Array Test Pattern 206 Figure 16 2 The MIRAC Main Screen with the detector at room temperature 207 Figure 16 3 Boeing HF 16 SrAs array unit cell 208 Figure 16 4 HF 16 multiplexer 209 Figure 16 5 HF 16 clock timing 1 209 Figure 16 6 Array timing with reset control for burst mode 210 Figure 16 7 Signal processor pixel timing 211 Figure 16 8 Array read timing with chopping 211 Vili MIRAC User s Manual List of Tables Table 2 1 Magnification and Pixel Sizes 6 Table 2 2 lt MUR AC Millets ste 184 dash es deta ee eed ee dat auton 7 Table 2 3 16 Array and MIRAC System Properties at 11 7 um 8 Table 2 4 MIRAC3 Background Sensitivity and Noise IRTF 3 m Telescope 10 Table 2 5 Telescope and Sky Emissivit
184. h makes it easy to enter the offsets for each integration Make sure that the directions symbol which indicate N S E W is pointed in the proper direction according to the orientation of the array on the screen This indicates to the program the proper orientation of the data array on the sky The orientation can be checked by taking an image of the standard star noting its position and then moving the telescope by several arcsec in a known direction and then take another integration to see the new position of the star on the IR array The normal settings for the SO 2 3 m telescope are X and Y flips on N up and E to the left In MIRAC the offsets are entered in arcsec of angle or in pixels in both RA and Dec and converted into seconds of time for the telescope commanded offset In the OBS Telesc Telescope control Position Commands menu the RA offset is entered in seconds oftime The telescope console display offsets are relative to the current position in seconds of time Note that the X and Y flip options only control how the data is displayed in the main image display screen The way the data 15 stored in disk files is unchanged Therefore the same gain mask and flat fields may be used for flipped and unflipped images If flips are used the data will still be unflipped when displaying using the functions under DISP Begin This display can be flipped with UTIL Arith X Flip and Y Flip The flip settings do have an effect on the UTIL Funct
185. hat should be used even at very low flux levels Out of range high is a count of all pixels excluding masked ones for which the value is greater than the fixed linear maximum or greater than the A D maximum minus 50 Out of range low is a count of all pixels excluding masked ones for which the value is less than the A D minimum plus 50 or less than the zero flux value minus 50 The ratio of the measured background noise to the calculated BLIP noise for the given background is given as BLIP This number should be 1 0 to 1 2 when using the broadband filters When there is a bright source in the field or high sky noise or when using the 2 2 and 3 8 um filters this number will be larger The blip noise calculation is totalnumber on source frames g MEC x skyflux blank flux x BG blip a 1 grab a 2 chop or nod a 4 chop and nod BG electron gain times dispersion at the detector g electrons unit 64 MIRAC User s Manual The status lines give the date time filename and object for the current observation and for the displayed image The observation time is updated every second At the right on the current line is the observing status Idle Data Save the remaining time out of total time for the current Observation and the remaining number of observations out of a total number of observations per run To the right of the display line is the display mode Current Operation Mosaic Replay etc The loca
186. he FlipFlopChop mode where the final image displayed is either the first or second image of the last chop pair With this mode when taking successive observations the program alternates the display between the chop beams A similar FlipFlop mode is available in the DISP Load Mode Replay function to examine past data 9 10 Telescope Control The telescope chopper is controlled by the camera electronics via the optical link to the PC This outputs a 0 V or 5 V level to move the chopper between beams The output id on s BNC cable hanging out of the back of the PC This should be connected to the chopper EXT input on the back of the chopper control box at the SO 2 3 m or the blue box at the IRTF which converts the logic chop signal to a bipolar signal that can drive the chopper 9 10 1 Nod Control by Logic Level The program can output a level indicating the current nod beam 0 V for beam 1 and 5 V for beam 2 Another possibility is to output a pulse to signal the start of the beam switch The pulse can be positive going 0 to 5 to 0 V or negative going 5 to 0 to 5 V The output for the pulse and level control is on the A D board breakout box on the BNC marked NOD This must go to the Wobble control box which accepts a level or pulse input and outputs the proper Mount Micro command to the telescope For the Steward telescopes the level control mode has been used successfully with MIRAC on the 1 5 and 2 3 m telescopes 9 10 2 RS 232 Cont
187. he camera is continuously read out and all images saved The speed is limited by the bandwidth of the ISA bus that the DSP card uses to communicate with the PC The data are saved temporarily to a RAM disk and are automatically moved to the Data File and Backup Data 72 MIRAC User s Manual directories at the end of the observation The number of images is limited by the size of the RAM disk and the maximum allowable DOS file size The present RAM disk is 32 Mbytes The packed files are 32768 2 N 4 bytes in length where N is the number of images For chopped data the number of images is twice the How many value selected For example for chop mode at 40 Hz there will be 80 chop half cycles per second and 2400 images in 30 seconds for a file size of 19 7 Mbytes The data can be taken in Grab or Chop mode no Nods allowed Also SaveAllObs must be ON and Ultrafast cannot be run in Simulate mode The final image of the set can be displayed to the screen The data are saved as 16 bit integers in unreordered format The individual images are single coimages no coadding is done on the DSP board so 16 bits are sufficient The MIRAC unpacking routine UTIL Functi Unpack Fast Data Files reorders the data and saves the images in the normal mirac format The mrc2fts program unpacks and reorders the pixels and saves the images as fits files The displayed last image can use the usual mask flat field and gain functions An additional option is t
188. he crate first must be threaded through a wall opening into the control room with enough slack to conveniently reach the power supply and PC At the S O 2 3 m telescope it is routed from the east side of the pier where the excess is left on the floor around the yoke and hung from a cable tray leading into a small electronics room and thence through an opening onto the counter in the control room At the IRTF the cable is threaded under the wall into the computer room under the false floor and thence to an opening in the floor at the table where the PC is setup At UKIRT the cable is threaded though a hole in the wall directly into the control room Normally a telescope facility dual fiber optic cable running from the Cass focus to the control room is used If this is not available such as at UKIRT and it is necessary to use the MIRAC fiber optic cable a moderate length is shipped in Crate 5 separate from the rest of the cable bundle The fiber cable ends are covered with red or black plastic protectors and small black tips In the telescope chamber as much as is possible the cable should be strung while it is being removed from the crate to keep it off the floor The cable should be supported by the MIRAC Velcro straps with buckles At all cable support points if the MIRAC fiber optic cable is used care should be taken not to squeeze it with the support strap to avoid damaging the fibers At the S O 2 3 m telescope the cable is routed from
189. he dichroic dial readings Step 3 It is sometimes useful to confirm the alignment by viewing the out of focus image of a bright star at 2 2 um This should produce a uniformly illuminated symmetrical doughnut with a dark central obscuration This is not sufficiently sensitive and unambiguous for the actual alignment A14 12 Setting the Telescope Chopper Parameters For an extended source the chopper throw should be set large enough to chop completely off the source or off the array field 30 to 50 arcsec For a compact source the chopper can be set for 5 22 99 14 Hardware Preparation and Setup 199 both beams on the array with a throw a little less than 1 2 the field The chopper direction should be chosen for best imaging at each telescope On the IRTF the chopper direction and throw can be set from the control room The preferred direction is North South The chopper reference BNC connector must go from the MIRAC PC to the IRTF blue level shifting box thence to the chopper sync input The chopper should be set to square wave external reference On UKIRT the chopper direction and throw can be set from the control room The best direction is North South On the S O 2 3 m the direction is determined by orientation when the secondary assembly is mounted The best orientation is in declination The throw is determined by the position of two rotating cam plates which form the mirror motion stops These should be cautiously rotated us
190. he distance from the power connector to the left most Velcro tie should be 54 inches In the upper fight figure the loop should drop to 41 inches above the floor 190 MIRAC User s Manual Figure A14 8 IRTF Cable Routing to Control Room Note that in the top figure the cable loop from the telescope yoke is incorrectly hung up on the corner of the MIM 5 22 99 14 Hardware Preparation and Setup 191 Cable Connections Control Room Power strip to clean power Power cord from Camera Power Supply to clean power Power cords for PC and laser printer lab only to power strip Power cord from computer monitor to power strip Computer monitor to monitor connector on back of PC Computer keyboard to keyboard connector on back of PC Ethernet cable from Ethernet to Ethernet connector on back of PC 50 wire ribbon cable from A D Digital I O Interface to A D connector at back of PC RS 232 9 pin cable from telescope control input connector to telescope control COM2 RS232 connector on back of PC Steward Obs telescopes only For logic level telescope nod control bit 0 of A D Digital I O Interface to telescope nod level input Chop BNC cable from telescope chopper external reference input to BNC cable at back of PC Parallel cable from input of laser printer to printer connector on back of PC lab only Cable Bundle Control Room End The captive beige velrco straps on the cable bundle should be opened to separate the cables ne
191. he filter wheels remove the bridge bracket which holds the wheels in place The first wheel accessed is wheel 2 the middle wheel is wheel 3 and the wheel closest to the optics mounting plate is wheel 1 Wheels 2 and three can be removed from the shaft The micro switches must be depressed to avoid damaging them with the gear teeth Take extreme care not to lose any of the sapphire spheres that form the axial bearing and heat sinking Also pay careful attention to the placement of radial bearings washers and springs When reassembling make sure all surfaces are clear Wheel is removed in the opposite direction from the shaft It is necessary to loosen the set screw at the optical baffle to free the shaft When reassembling the set screw should be tightened while pressing on the black hub to compress the axial loading spring When removing filters from the wheels take extreme care that screw driver does not slip and scratch filters There is a cardboard protector in the MIRAC Working Files Cryostat Assembly folder which should be used Use filter disassembly box placing the filters and spacer washers carefully in the correct compartment on small Kim wipes so surfaces do not contact A19 5 Removing the upper section of LN2 radiation shield 1 2 Unscrew LN2 shield temperature sensor and lift tape holding the wire to the radiation shield Take care not to damage the aluminum foil on the radiation shield Remove the slotted ven
192. he macro F3 Findstar It is not necessary to nod at 2 2 um Focus IRTF nominal value for MIRAC is in Table 7 3 Focus procedures are described in Sections 7 8 and 7 9 Check chop and nod throw Choose whether to put object in all four chop nod beams Chop 20 arcsec N S Nod 20 arcsec E W center source in one quadrant or chop and nod completely off the array field Chop 50 arcsec N S Nod 1 60 arcsec E W Find initial standard star and begin observing sequence To find object first acquire nearby visible catalog star at 2 2 um Observing sequence First Wavelength Standard star Object Standard star Second Wavelength Standard star The total cycle should take at most one hour Image scale Observe a standard star with chop and nod throws set for the source in one beam and offset file standard off with star initially centered at center of array See Section 7 13 for determining the image scale from these images Gain Map flat field determination Set the following parameters OBS Next Chop Nod Grab Integration Time 2 sec How Many 10 Frame Time for dome flux in linear region OBS Header Observe Chop Frequency Low for frames coimage total frames Y Level Med for dome low for sky For each observing filter with frame time set appropriately obtain a set of images on the dome preferably away from the shutter with the shutter closed and a set of images of the sky at the same declination and hour angle a
193. he next six reads a 6 5 msec chop wait the array is reset but the coadder output is not used A minimum of one chop wait read is required to prevent a pixel integration from being partially in each of two chop positions For the next eight reads the array is not reset so the charge integrates on the integrating capacitor At the following read the array is reset and the coadder output written to the coadder memory The process repeats for a total of four frames coadded for one chop half cycle when coadder output is again written to the FIFO memory data ready signal informs the PC computer that a co image is ready and the image is read successively from each of the 16 Checking and Trouble Shooting 211 lt 16 Cycles 1 0667 usec BIT CLOCK FAST CLOCK ANALOG SIGNAL CONVERT PULSE HOLD amp CONVERT PL AM COADDER ADDRESS
194. he storage dewar The transfer tube should first be cooled down by slowly inserting it into the storage dewar with the pressure relief and vent valves closed Then the transfer tube can be raised and inserted into the MIRAC inner chamber The warm transfer tube inserted into the supply dewar usually raises the pressure 182 MIRAC User s Manual sufficiently to transfer If not a rubber bladder can be used to alternately warm some helium gas from the dewar and squeeze the warm gas back into the dewar to induce boil off and raise the pressure With the MIRAC transfer line and a storage dewar pressure of 2 psi it takes about 15 minutes to cool down the cryostat chamber to the point where the LHe starts to collect and another 15 minutes to fill the chamber This is for a low transfer rate to conserve LHe during the cooldown The LHe consumption is about 8 liters At the IRTF and UKIRT the transfer line requires a pressure of 2 to 5 psi The first fill will boil off in about 5 hours The detector will reach 4 3 about 1 5 hours summary of the LHe cooldown is given in Figure 14 2 After completing the LHe fill the LN outer chamber should be topped off At this time the threaded fitting with the long tube should be installed on the LN2 vent and the safety fitting with the release valve and Bunsen tube installed on the LHe vent The LHe safety cap should be on the LHe vent at all times except during transfer to prevent air entering the LHe fil
195. hop Nod off Number 1000 Obs Header Observing Parameters Read time 2 2 msec Frame time 75 msec Chop delay 15 4 ms Chop frequency 3 hz Integration time 5 or 1 sec Obs Header Filters 2 2 open Obs Save off Disp Init Statistics on Fit Gaussian Autorange Min max Min 2 Max 5 Disp Begin Gray Gray Y on Step 1 Set the telescope focus and the location of the guider box TV relay lens to the values recorded in the log for the last observing run Also note any information on misalignment of the finder telescopes Step 2 Point to the brightest star available This should be visible perhaps way out of focus in the on axis TV and MIRAC If it is not immediately available try a 9 position search around the initial MIRAC field If this is not successful on the IRTF and S O 2 3 m telescopes try Step 3 Step 3 Star not found with initial effort Remove the cover plate above the relay optics assembly on the guider box Flip the viewing mirror lever on the right side of the guider box You should see the telescope secondary brightly and uniformly illuminated as a doughnut Guide the telescope to achieve this with your eye at the center of the guider box opening You can also use a jeweler s loop as an eyepiece to try to locate the stellar image It should be an inch or two outside the guider box Change the telescope focus to put it there Reposition the flip mirror to the normal position and try to find and focus the star with
196. hopping is in one direction Dec and nodding in another RA The sequence is as follows First with the telescope pointed so that the source is in one of the chop beams the chopper is run and the camera coadds frames into the two separate buffers for the time interval given by the integration time One buffer contains the source plus background the other contains only background Next the telescope is nodded to a different sky position and two more background images are obtained and stored in two additional buffers These four images constitute a single observation After the observation is complete the telescope is returned to its original position and the four images individually stored in the observation file and combined to provide a realtime image with background subtracted It is also important to offset or dither the images This is for the following reasons 1 Moving the source around minimizes any array dependent effects such as bad unresponsive high dark current or noisy pixels or errors in the gain map It insures that these do not compromise any one area of the image 2 Offsetting by fraction of a pixel increments improves the resolution of the final image since the observations can be registered to the nearest fraction of a pixel before combining 3 For some extended sources such as planetary nebulae the entire source may not fit completely on the so a number of positions must be taken simply to observe the en
197. i Fits Output utility as described in Section 12 5 202 MIRAC User s Manual 5 22 99 A 15 MIRAC Cryogen Instructions 203 Appendix 15 MIRAC Cryogen Fill Instructions at Telescope MIRAC3 LN2 and LHe must be topped off once per day preferably at the end of the night normally by the telescope operator The hold times are LHe gt 40 hrs quiescent and gt 30 hrs operating LN2 gt 34 hrs The following instructions were developed for the IRTF l Close the LN2 shutter by pushing the actuator nearest the window all the way in up and then retracting it fully This is an end of observing night task The shutter must be reopened at the start of the night by inserting the actuator into the slot rotating to capture the fitting and withdrawing Remove MIRAC from the Telescope a b d e f a b d Position the yellow scissors cart under the camera oriented N S with the handle toward the North Place the MIRAC foanyplastic sled crosswise under the camera with the thin end under the cryostat Raise the cart to almost contact the camera Loosen the socket head screws on either side of the camera mounting plate and withdraw as far as possible Raise the cart and camera sufficiently to release the mounting ball from its cradle Slide the sled and camera West to clear the ball from the cradle Lower the cart surface to about 30 inches from the floor Move the cart N W to clear the telescope sufficiently f
198. image The detector temperature is updated every second the other temperatures every five seconds and all other parameters when they are changed or when RUN or CAMERA INIT are executed The only exception to the current parameter display is in the Display Replay Mode for which the parameters contained in the file headers for the displayed images are shown REPLAY Mode E Exit C Continue File Header displayed below Obs Mode Chop Nod Log Sav 10 00 Chop Hz gt AMBT emp 4 37 Off Dec 10 00 FrTimetCms EleTemp 19 31 Filtr 1 CUF Burst Mode A DTemp 47 23 Filtr 2 BaF2 IntTimets DetTemp 6 125 Wavelth 12 80 Section Full Data gt Max 12 82 lt 91 103 3 63 lt 30 123 Fit Max 13 13 91 34 102 835 FWHM 3 53 Chisa 0 004 Total RMS 0 40579 Avg 0 0364 Num 16384 Background RMS 0 30556 Avg 0 0510 Num 16035 Sum 239 0 Num 349 lt Flux 2110 8 RMS 21 83 DIF 0 7 A D lt 5415 1320 FrameErrors Flux MaxMin lt 4085 1517 gt BLIP 1 36 Lev Medium OutOfRange 18 o gt 13 51 59 DISP 9 12 97 8 20 04 97 g d970912 c970912a 115 gamma adl Mode Replay Figure 9 1 MIRAC Main Screen OBS Command Line The array data is displayed as a grayscale or false color image Whether current or past data the raw images be processed by adding or subtracting chop and nod images and applying a mask flat field and gain map as desired The c
199. ince this is the most satisfactory way to characterize the camera The point source sensitivity depends as well on the image spread due to telescope image quality chopper image degradation and atmospheric seeing and diffraction Evaluating the point source sensitivity requires determining the equivalent number of pixels for background noise due to the point source image spread This is discussed by King for pixels small compared with the point spread diameter PASP 95 162 1983 He gives the equivalent noise solid angle to be C 0 where 0 is the FWHM for the image The constant C is 2 7 for an Airy disk and 11 for a seeing mode The point source sensitivity can be calculated as the surface brightness sensitivity times Sqrt C 0 We use a simplified point source sensitivity calculation The point source noise is determined from the surface brightness noise by assuming 1 2 the signal appears in a disk of the root sum square of the diffraction FWHM and seeing FWHM taken to be 5 arcsec at the IRTF 10 MIRAC User s Manual Table 2 4 MIRAC3 Background Sensitivity and Noise IRTF 3 m Telescope Backgnd Noise 1 sigma in 1 minute Wave Diffraction Frame pixel Surface length FWHM time Digital Sensitivity Brightness Point Source um arcsec msec Units Jy Unit mJy arcsec mJy 2 2 0 16 70 635 035 5 9 5 5 12 6 3 8 0 27 70 1470 029 6 5 6 6 11 4 4 8 0 34 70 2320 057 16 17 9 9 7 9 0 56 50 2710 40 204 270 5 9
200. inear operation as monitored with an oscilloscope attached the a Signal Processor test plug DETS should be adjusted for a DETS current of about 10 14 pA The cryostat input output wiring should be checked each time the cryostat is disassembled The bias voltages should be checked and adjusted before the camera is connected to insure that the detector will not be damaged This can be done by monitoring the voltages at the digital cable connector or the bias monitor board with the short ribbon cable With the camera operating the bias voltages and currents can be monitored by measuring the voltage and voltage difference of each bias pair of test pins on the monitor board 215 ostat Inputs and Outputs 17 Cry 5 22 99 BRIT puts Detector Room Temperature 14 EEHEEEEEEEEEEEEFREREE ESESEELEELLESEEENEEEEEEE 322 3 Table A17 2 Bias I a _ _ _ En ii E rekke ekee SDE EE H EIE mE MIRAC User s Manual 216 ty at Room emperaus T Detector Continu Lb pesas OTT d ELR BFEEEEEEREPEDEBEBEE EEEEEEEEEEN Lipsia TT TTT TTT TTT
201. ing 5 64 inch allen wrench as a rod The chopper should be run at 10 hz internal with the Amp at 1 o clock Function dbl The correct position can be judged by the sound Then it should be checked with a star moving from one beam to the other Return the Signal Source to external for operating the camera A14 13 Checking the Telescope Collimation It is a good idea to check and adjust the telescope collimation at the beginning of the run There are secondary tilt collimation adjustments with readouts on the IRTF telescope control console The collimation should be done after the dichroic adjustment It can be done by the first method below in daylight There are three possible approaches 1 Centering the beam from the camera and secondary mirror onto the primary To achieve this run the camera in scope mode monitoring columns 1 and 128 at 11 7 um with the telescope looking at the sky tracking off Set the display scale to give good sensitivity Set the chopper angle and throw as desired and check it in chop mode A chop sequence will stop with the chopper in the on source beam The telescope should be close to nominal MIRAC focus a First Option adjust collimation for the on source beam This is appropriate for a large chopper throw and when the source will be in only one chop beam Tape strips of projection transparencies on the monitor as fiducials Change the RA collimation At some point some of the beam should go off the edge
202. ing airmasses from observing list OBSLIST EXE used for creating and editing an observing list TMONITOR EXE stand alone temperature monitor program with data saved in a file VGADEMO EXE MIRAC HLP on line help for MIRAC program TCSCMD TXT CATALOG DIR various source catalog files SSAO DIR Star catalog files UNIXPROG lt DIR gt C programs for unix supporting programs 144 MIRAC User s Manual Files that should be in the observing directory e g O IFTF1294 these files are not all essential to run the program but it is helpful to start with previous files in these categories AMS airmass listing generated from chosen CAT file for date and site CAT catalog source files for MIRAC and Steward Obs Telescopes RT catalog source files for IRTF catalog source files for DAT catalog source files for UKIRT CMD command files GAN gain maps such as 781209 GAN FLT flat field maps such as LAB1294 FLT FRM filter frame time link files HDR header files such as CURRENT HDR STANDARD HDR LOG log files of the form 12 09 94 LOG generated during a run MACRODEF MRC macro function key assignments MRM macro files such as PRINT MRM MSK mask files such as INHL1209 MSK image noise high low SCOPEHDR PRM header parameters for the scope mode SPC plot parameter files such as MRCLINE SPC OFF text offset files Files that should be in the data file
203. ing transfer loss once per day but not supply dewar boil off I am assuming we will consume 5096 more on Mauna Kea because of less efficient transfers We will try to use transfer techniques that minimize the transfer loss Transfer tube We will use IRTF flexible transfer tube Can you give this a good vacuum pump down before we arrive Nitrogen gas Require regulated N2 gas to assist removing LN2 from cryostat Nov 5 Thu Control room setup Nov 4 Wed prior to MIRAC team arrival Table along computer room east wall Quiet power strip less that 1 kw Thin ethernet with transducer to mate with thick cable Two monitors for telescope status and guiding video BNC cable to chopper reference interface box Dual fiber optic cable from computer room table to Cass at telescope We are depending on the IRTF fiber cable Intercom mike Telescope paddle Focus control paddle On axis mirror control button Instrument Mounting Require MIRAC interface plate stored at IRTF Usually mount on south station Nov 5 or 6 Thu or Fri mount MIRAC on telescope MIRAC3 must mount with the window facing East instead of North as with MIRAC2 This means that the electronics box extends west of the cryostat If there is interference with other equipment It might be possible to mount the electronics 5 22 99 3 Observing Run Arrangements 17 on the south or north side of the east facing cryostat I will send a sketch by fax Off axis Guider We would like
204. ion A19 5 Item 9 use a caliper to make sure that the LN radiation shield is centered with the LHE cold work surface before tightening screws Take care to make sure that all actuators rods and support posts are installed Inspect O ring surfaces Smooth scratches with rouge paper if necessary On occasion remove rings using a Q tip stick cut with scissors to a sharp end Clear ring with Kim wipe and grove with a Q tip Regrease ring sparingly Pumping the cryostat with a vacuum pump should be done according the instructions in Section A 5 22 99 20 VMS DOS UNIX Command Reference 227 Appendix 20 VMS DOS UNIX Command Reference A20 1 Command Cross Reference Guide Description VAX VMS DOS UNIX Set search path assign path logical path set path Set terminal type set term inquire N A setenv TERM Change login password set password N A passwd Display the date show daytime date date Display the time show daytime time date Online help facility help N A man Online tutorial login to tutor N A learn Show all active users show users N A who w Display a file type type cat Page through a text file type page more more Change a file s protections set protection attrib chmod Copy files copy copy cp Delete files delete del erase rm Rename files rename rename mv Print a file print print Ipr Search a file for a pattern search find grep Locate a file dir find find Show difference bet
205. isplay gt Factor for VGA Bin 1 Grid Display x Autoramge Settings gt p Fit Function None p 5tatistics and Gaussian Moffat Stats Display On Fit Function Gaussian Object Detection Sigma 3 0 Source inclusion width factor 3 0 p Region for stats Limit for BKG Iterations 3 Moffat Beta term 1 000 A Full Map Calculate Source model sum Off B Lower Right Weight data in fit Off Cy Upper Right Region for stats Full Map D Lower Left Invert new data Off E Upper Left F Right Half G Left Half p Autorange Settings H Upper Half I Lower Half Autorange Mode MinMax Noi L J Noise Min factor 2 00 Max Noise factor 5 00 p BLIP Parameters Detector Electron Gain 1 91 Horizontal flip On Electrons per ADU 3191 00 Vertical flip on Blanked off Flux ADU 0 00 Transpose Off IL Jl Direction indicator On North Direction Up East Direction Left Screen Mode Colors 3 A Default VGA B 64 Gray level Monitor Color 16 Gray SVGA Log levels 16 gray only off D Blue Red Yellow SVGA VGA Screen Mode Heat SVGA Heat SVGA USER color file test4 pal User Defined Force B W mode Off J 5 22 99 12 2 DISP Command Line Menus 153
206. jname is the object name If ais entered without any arguments program prompts user for data d delete object s from list number n or all of type TYP i insert added source at object number n q query mode confirms that you want to delete the source 1 number of lines per object list page default 66 r specify range of objects to read in where n1 and n2 are the start and end object number if list changed output new list to outlist default output file is same as sourcefile s sort the entire list by The objects of type SAO will be placed following the target object t output a file for SO telescopes ti output a file for the IRTF telescope tu output a file for UH telescopes tk output a file for UKIRT p print out object list after other operations are complete If a type string is included only those types are printed m merge two source lists Sourcefile is the primary file any objects not in sourcefile but in otherlist will be added If the source exists in both the sourcefile entry is used The sources are added to the end of the list unless sorting f find SAO catalog stars for the targets The number n specifies the number of SAO stars to find for each source The optional path tells where the SAO data files are located The sources are automatically sorted in this option 5 22 99 4 OBSLIST Program 121 Regardless of the order of the command line switches the program proceeds the followin
207. k dormitory rooms meals cryogens and equipment transportation should be made about 10 days in advance with the Steward Observatory operations office Penny Schmitt Room 350 Tel 520 621 7659 Normally three Steward Observatory downstairs dormitory rooms are reserved for 90 inch observers More than three observers in the telescope control room require permission from the director in advance The normal cryogen requirement for up to eight nights is a 60 liter dewar of LHe For a four night run a 30 liter dewar would be adequate if the cryostat is precooled in Tucson The equipment can be transported to and from Kitt Peak by the Steward Observatory day crew using an enclosed van The van leaves at 8 00 in the morning 3 2 2 Mt Hopkins Arrangements For information on arrangements for Mt Hopkins check the MMT home page Section 2 1 3 2 3 Hawaii Mauna Kea Arrangements Travel arrangements For observing in Hawaii it works best to arrive at the mountain lodging Hale Pohaku the evening of the third day before the night observing begins and to depart the morning of the day after the end of the last observing night The arrival time allows the first evening for taking the cryostat to the summit to put it on a vacuum pump one full day for instrument setup cryostat cooldown and test and a second full day for correcting problems On the observing day one half day is devoted to mounting the instrument setting up in the control room and
208. l line causing an air ice plug LHe consumption is approximately 8 liters cool down and first fill plus 4 liters per day transfer thereafter A14 3 5 Topping Off Liquid Helium Reservoir With a supply dewar pressure of a few ounces with the MIRAC transfer line two liters of LHe should transfer in about 5 minutes For a pressure of 3 to 5 Ibs at the IRTF and UKIRT this will take about 10 minutes The LHe safety cap should be on the LHe vent at all times except during transfer to prevent air entering the LHe fill line causing an air ice plug A14 3 6 Cryogen Transfer at the Telescope Instructions are given in Appendix 15 A14 3 7 Measuring Cryogen Levels The MIRAC level sensor indicates full scale at room temperature When it reaches a liquid nitrogen surface the reading drops to 0 8 of full scale It recovers to full scale slowly after being raised above the surface As the level sensor is lowered in to the LHe chamber the reading slowly drops to 0 2 of full scale When it reaches the LHe surface the reading abruptly drops to zero The reading recovers immediately to 0 2 of full scale when the sensor is raised above the LHe level It is important to insert the sensor very slowly into the LHe chamber to avoid rapid boil off and loss of cryogen 5 22 99 14 Hardware Preparation and Setup 183 A14 3 8 Cryogen Capacity Hold Time and Consumption The cryostat capacity remaining cryogen as a function of level and hold time is given in
209. lanked off camera output then count detents and watch the display to reach the desired pupil The actuator should then be fully withdrawn Table A14 4 Cryostat Pupil Slide Position Hole Dia Focal Ratio Telescope cm f 1 CW Blank 2 167 45 S O 1 5 2 3 m 3 196 36 8 UKIRT 4 231 30 CTIO4m 5 420 17 6 SOFIA 6 CCW 470 15 2 MMT 6 5 m The magnification slide is continuously adjustable between magnifications 43 and 1 14 with 7 fixed detent positions as given in Table 14 5 The magnification actuator is the one closest to the vacuum valve equidistant from both filter wheel motors The actuator must be inserted and rotated counterclockwise until it engages the slide key then rotated counterclockwise looking up towards the bottom of the dewar to be captured Pushing in until it stops with a small space between the knurled knob and the dewar base plate moves the stage to the highest magnification position To move the slide from high to the next detent position withdraw gently while feeling for the detent The actuator must then be rotated clockwise to disengage the slide and fully withdrawn The motion of the slide from lowest to highest magnification is 5 3 cm The nominal detent for IRTF and UKIRT is the fully out positions magnification 43 This gives plate scales of 33 and 27 arcsec pixel and field sizes of 42 and 33 arcsec for the IRTF and UKIRT respectively 5 22 99 14 Hardware Preparation and Setup 195 Table A1
210. lator LM7815 LM7915 LM7815 LM7915 LM337H LM7905 LM7815 LM7915 LM7805 LM7815 LM7915 Supply Watts Temp Monitor Pos Supply 1 2 Preamp 3 Bias 4 1 5 6 7 Signal Proc 8 Signal Proc 9 Digital 10 11 Total Temp Monitor Table A18 2 Power Supply Ratings Spec Input 23 23 23 23 12 9 23 23 10 23 23 Cable Watts 25 24 13 20 01 2 5 3 6 3 4 49 09 05 59 5 Minimum Input 17 7 17 7 17 7 7 5 17 7 Electronics Watts 2 7 3 0 1 8 1 7 6 10 1 41 1 38 6 83 9 1 5 8 185 8 5 22 99 19 Cryostat Disassembly and Assembly 225 Appendix 19 Cryostat Disassembly and Assembly A19 1 Basic cryostat disassembly 1 2 3 4 5 6 7 8 Release cryostat vacuum This is best done with gas with a pressure about 2 psi Let gas into the cryostat slowly to avoid large pressure differences which could damage the radiation shields and optics housing Clear work table and provide electrically conductive pad and wrist cuff Collect Cryostat Disassembly tools and screws plastic box Camera Setup plastic box Mechanical tools plastic box Two or more large plastic bags for covering parts Small freezer bags for small parts Latex gloves Lab tissues Cotton swabs Alcohol O ring grease MIRAC cryostat assembly skirts located in the MIRAC Working Files Cryostat Assembly folder Set cryost
211. ld have been completed The Nightly Startup Tasks Section 6 1 should be carried out along with the setup tasks as indicated 1 Turn on MIRAC PC and monitor Ifa floppy disk is in the floppy drive it must be removed Computer should boot connect to the network and show the DOS prompt To use a laser printer connected directly to the MIRAC PC turn on the printer before running MIRAC Prntinit will be automatically executed to download grayscale character font 2 MIRAC program backup floppy disks In the event of program loss or corruption the MIRAC backup floppy disks include a floppy boot disk and all directories and files required to operate MIRAC These are packed in Crate 8 3 Establish network connection after moving to a telescope After MIRAC has been moved to telescope from the DOS prompt execute the appropriate command NETSOKP NETIRTF NETUKIRT NETMANOA NETMMT NETLAB or NONET The appropriate network program PCNFS or PathWorks will be selected with the required settings for the given telescope and the computer will be rebooted The I and J drives should be automatically mounted on the host computer with the subdirectory MIRAC At the Steward Observatory 2 3 m telescope bokobs default log in directory u3b bokobs MIRAC User s Manual i ulb bokobs j u3b bokobs largest disk space At the IRTF MIRAC will use a guest account created by the first observer It is necessary to request that the IRTF syst
212. le which provides the TCP and UDP transport services that allow an application to access the underlying network It is a TSR program which uses about 60 Kbytes of memory RTM is required for using the IRTF programs which perform the beam switching and offset functions via Ethernet Use the cleaning diskette and clean the PC floppy drives Carry out Nightly Startup Tasks 1 6 Check program values Obs Init Program Values TCS command confirm off S O 90 in on RS232 CHKSUM off S O 90 in on Min chop wait cycles 1 lt esc gt 10 Check Mode entries Obs Mode Fast data mode off normal mode Continuous coimaging off Ask for offsets off Beep off Do all offsets in 1 run on Off would require executing Run for each offset position lt esc gt 11 Carry out Nightly Startup Tasks 7 8 12 Check Observing Parameters Obs Header Observing Parameters Burst mode off Sample mode single Level of flux medium 24 MIRAC User s Manual Level of off src chop beam normally set to 1 esc Chop and nod parameter settings are given in Section 6 1 Nightly startup tasks Item 9 13 Check Telescope and site Obs Header Telescope and site Confirm that site and telescope are correct esc 14 Check Optics parameters Obs Header Filters and Optics Arcsec pixel 133 27 UKIRT for cryostat magnification position 2 magnification 43 15 Check telescope control parameters Obs Telescope Telescope control
213. le A2 3 The MIRAC entries are an inhomogeneous set which cannot be relied upon to more than a few hundredths of a magnitude The usefulness is that they cover all MIRAC filter bands The Cohen and Hanner entries should be more internally consistent and accurate However some of their values differ from each other by a few hundredths of a magnitude as well The Objects marked with a plus are most commonly used as standards with MIRAC Beta And Alpha Ari Alpha Tau Alpha Aur Alpha Ori Alpha Car Alpha CMa Alpha CMi Beta Gem Lambda Vel Alpha Hya IRC 10216 Mu UMa Epsilon Mus Gamma Cru Alpha Boo Sigma Lib Alpha Sco Alpha Her Gamma Dra Eta Sgr Alpha Lyr Gamma Aql Alpha Aql Mu Cep Beta Peg MIRAC Cohen Hanner MIRAC MIRAC Cohen Hanner MIRAC MIRAC MIRAC MIRAC Cohen MIRAC MIRAC Cohen Hanner MIRAC MIRAC Cohen MIRAC MIRAC MIRAC MIRAC MIRAC Cohen Hanner MIRAC MIRAC MIRAC MIRAC MIRAC MIRAC Cohen MIRAC Hanner MIRAC MIRAC Cohen MIRAC Hanner Table A2 1 Standard Stars with Magnitudes Ordered by Right Ascension RA 01 06 02 04 04 33 05 12 05 52 06 22 06 42 07 36 07 42 09 06 09 25 09 45 10 19 12 15 12 28 14 13 15 01 16 26 17 12 17 55 18 14 18 35 19 43 19 48 21 42 23 01 35 21 23 13 16 24 45 56 07 23 52 40 16 38 05 21 28 08 43 14 08 26 13 31 41 45 67 41 56 50 19 26 25 05
214. le in the o irtfMMYY directory to your data directory 5 22 99 8 Short Form Instructions 8 4 5 Backup Start tape backup with DOS command write If you want to backup by ftp ing files to a home computer start now or later Don t forget your log file 8 4 6 Turn off the MIRAC PC and monitor or leave it running if writing a tape 8 4 7 Hardware checks Check that LN2 slide at camera is CLOSED 57 58 MIRAC User s Manual 5 22 99 9 Using Program 59 9 Using the MIRAC Program 9 1 Running the MIRAC Program on a PC Stand Alone The MIRAC program can be run on almost any PC under DOS or under a DOS window in Microsoft Windows or Linux The program with readme txt instructions and required files can be obtained from the MIRAC home page Section 2 1 under Observing Programs mrcfiles zip The program contains a simulator mode which blocks hardware related commands and simulates data taking This can be turned on in the menu OBS Init Simulation Parameters Simulate data On parts of the program can be run in this mode 9 2 Directory Structure The MIRAC3 EXE and MIRAC BAT programs must be in a directory in the DOS path This is presently C MIRAC When the MIRAC program is executed the program searches the path to find where 15 located and then uses that directory as the program directory This is where it looks for MIRAC HLP MIRAC FIL and the printers file The printers definition file
215. led spectrum of this star Alpha Lyr Var Var Alpha Ori Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star Var Semi regular pulsating star 112 Alpha Sco Alpha Tau Beta And Alpha Boo Beta Gem Beta Peg MIRAC User s Manual Has readily observable extended dust envelop making it a poor choice for point spread function reference Radial velocity variations with a period of 1 yr were detected by Smith et al 1989 AJ 98 2233 Suspected Var Semi regular pulsating star Radial velocity variations with a period of 1 yr were detected by Smith et al 1989 AJ 98 2233 Var Var Larson et al 1999 ASP Conf series find that this star has radial velocity variations on the order of 1 to 2 years Hatzes amp Cochran 1998 A amp AS 128 207 detect long term radial velocity variations Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star Hammersley et al 1998 do not detect variability at mid ir wavelengths using IRTF and they include it in their new list of mid ir standards Suspected Var Var Larson et al 1999 ASP Conf series find that this star has radial velocity variations on the order of 1 to 2 years Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability i
216. linear and that the out of range pixels are 0 0 when the highest 18 dark current pixels are masked with hill 14 msk When OBS Next Link Frame Filter is on and the files sky frm or dome frm are chosen these values are 42 MIRAC User s Manual automatically set for the selected filter These files can be edited or new frm files created in OBS Header Hardware Frametime filter links Table 7 2 Filter Change Times Small CVF change 7 8 to 8 0 um 3 seconds Large CVF change 7 8 to 13 um 6 Adjacent fixed filter change 8 8 to 9 8 uum 3 Distant fixed filter change 8 8 to 20 6 Q3 15 Large change with both filter wheels changing 29 7 4 Macro Aids Macros can be run from the function keys or from OBS Next Macros They be used to automate the settings in the next menus for various types of observations New macros can be created saved and assigned to macro keys They are created by recording the keyed sequence while it is carried out starting and ending with Alt M and saving with UTIL Macro Save The maximum allowable key strokes in a macro is 255 The current macro key assignments are given by UTIL Macro Display Macro Definitions Up to 10 macros can be assigned to a key with UTIL Macro Assign Macro to a Key The macros in the observe directory can be listed from the DOS prompt with dir mrm The macros are ASCII files The files are cryptic with just the keys used to create the macro but they can be edited with the DOS
217. ll four Chop Nod Beams 9 9 1 4 Nod 2 beam This mode takes 2 images one at each nod beam position The mode is selected by setting the Grab Chop switch to GRAB and setting the nod mode to 2 beam nod First an image is taken in the first nod position then the telescope is offset and a second image 2 is taken The source is assumed to be in the first nod beam so the image arithmetic to subtract the background is 11 12 9 9 1 5 Nod 4 beam This mode is similar to the 2 beam nod mode except that a total of four images are taken first one image in beam 2 then 2 images in beam 1 then one image in beam 2 To select this mode the Grab Chop switch is set to GRAB and the nod mode set to 4 beam nod The purpose of this mode is to bracket the on source images with two off source images to remove the effects of any linear drift in the sky background The image is assumed to be in beam 1 so the image arithmetic for background subtraction is I2 I3 I1 I4 Note that for this mode the user selects the integration time for each of the four images so that the time spent on source will be twice this time In all other modes the source is only in one of the beams so that the integration time selected for each beam is the same as the on source time 5 22 99 9 Using Program 71 9 9 2 Fast Data Mode In the various modes of data taking the file that is saved to the disk contains a header and the on and off source images
218. lue or white are data Temperature monitor cable to camera electronics temperature monitor connector Filter controller RS 232 cable to filter controller 9 pin connector AC power cord in cable bundle to filter controller AC power cord A14 7 Temperature Monitor and Controller The temperature monitor controller is mounted at the back of the camera electronics beneath the connector panel The temperature monitor operates anytime the temperature monitor power supply switch is on and the cables are connected It provides five temperatures displayed on the MIRAC status display Ambient temperature determined by a thermistor on an 18 inch cable hanging out of the camera electronics connector panel Electronics temperature determined by a thermistor mounted on one of the signal processor boards marked at the edge of the board This should normally be between 20 and 30 C A D temperature determined by a thermistor mounted on an A D heat sink on one of the signal processor boards marked at the edge of the board This should be between 35 and 45 C not above 50 C 5 22 99 14 Hardware Preparation and Setup 193 Detector temperature determined by a Lakeshore Cryogenics diode mounted on the detector mounting stage This accurately measures the temperature of the temperature controlled stage but not of the detector itself which is poorly heat sunk to the chip carrier and is self heated to a higher temperature which depends on operating pa
219. mall manila colored cardboard square in the MIRAC Working Files Cryostat Assembly folder over the detector mask plate Tape the larger square over the LHe baffle opening Remove the two ribbon cables from the detector assembly and replace with shorting plugs Disconnect heater temperature sensor plug and the filter home switch plug small in line plugs taking care not to damage the wires Remove the detector slide actuator rod This is done by loosening the locking socket head head screw by reaching across the top of the detector mask with a 5 64 ball driver Note how screw mates with dimple on shaft Remove the 3 vented socket head screws in the optical assembly plate and a fourth screw on the filter wheel gear assembly below the optics plate and lift off the optical assembly taking care not to damage wires Put assembly aside under a protective plastic sheet At this point it is possible service the filters or to remove the detector assembly which ever is required 5 22 99 19 Cryostat Disassembly and Assembly 225 A19 3 Removal of detector stage assembly 1 2 3 Put on grounded wrist cuff steps in Section A19 2 must be completed first Remove four socket head screws at the base of the detector slide bracket The inner two screws are longer Set aside and protect the detector slide assembly taking care not to damage the wires A19 4 Removal filter wheels and filters 1 2 3 4 To access t
220. mera e 7 10 5 Quick look display and processing 11 13 Post observing data reduction A6 10 MIRAC files and menus All A12 Shipping and setup and test 13 15 Trouble shooting and service 16 19 Unix commands Tape Backup Weather and Address information A20 A24 MIRAC User s Manual 5 23 99 2 Overview Performance 3 2 Overview and Performance 2 1 on the World Wide Web The MIRAC home page can be reached on the World Wide Web with the addresses MIRAC http cfa www harvard edu jhora mirac mirac html Steward Observatory http www as arizona edu Steward Observatory Facilities Technology Development Mid Infrared Detectors and Instruments MIRAC3 MMT http www as arizona edu Specific Projects and Related Institutions Multiple Mirror Telescope Observatory MMT Instrumentation PI instruments MIRAC3 Harvard SAO Center for Astrophysics http cfa www harvard edu a number of telescopes CfA is involved in a number of other projects MIRAC3 IRTF http irtf ifa hawaii edu Facility Instrumentation Visitors Instrumentation MIRAC3 UKIRT http www jach hawaii edu UKIRT home html Instruments Visiting Instruments MIRAC3 recent results here The home page contains a MIRAC3 description sensitivity recent results MIRAC3 Manual work station programs for preparation for observing and for data reduction MIRAC camera PC programs and references 2 2 General Description of MIRAC3 Detailed
221. missions chmod nnn filename chmod c p c p filename n a digit from 0 to 7 sets the access level for the user owner group and others public respectively c is one user g group o others or a all p is one ofr read access w Write access or x execute access Setting Default Permissions umask ugo ugo is a 3 digit number Each digit restricts the default permissions for the user group and others respectively Changing Modification Time touch filename Making Links In oldname new name In s oldname new name Seeing File Types L S F 13 Encrypting Files Source Files crypt source encrypted Editing vi x encrypted crypt encrypted more crypt encrypted gt text Decrypting Files crypt asks for the encryption key 14 Searching with more Run more more filename 5 22 99 Next Line Return Next 11 Lines d Next Page SPACE Search for Pattern pattern Next Occurrence n Next File 15 Directory Stack Change Directory Push pushed directory Change to Top Directory Pop popped Show Stack dias 2 Commands 2 1 Command Line Special Characters Quotes and Escape Join Words Suppress Filename Variable Substitutions Escape Character Separation Continuation Command Separation Command Line Continuation Return 2 2 I O Redirection and Pipes Standard Output gt gt Appending to Standard Output gt gt gt gt Standard Input lt Stan
222. mpl plot mode One Trace Make Scope Header Obs Header Begin Scope Display Edit Scope Header Same as OBS Header Change Display Params Same as DISP Begin Contour Parameters Plot Params Edit A12 3 6 UTIL Camera Init Camera Begin Coimage Stop Coimage Fifo Reset Master Reset Load Col Reg Read Column Display Data Coimage Ignore Off Xmit Continuous Resets Number of frames coim Probe DSP Status 162 MIRAC User s Manual A12 4 PRN Command Line Menus PRN Init Mode Print OBS DISP UTIL Quit A12 4 1 PRN Init p Printer Initialize Printers gt Current Page 7 Add a printer Edit current Network lw Choose printer Delete printer Network lw Save Printers c mirac printers dat Read Printer file c mirac printers dat p Printer Parameters p Select Printer Printer Name Network lw Device LPT2 Console Maximum Width 140 DeskJet 500 HP Title Init ASCII codes LaserJet IIP HP Graph Init ASCII codes Text file mirac out Reset String ASCII codes Network PS LPT2 Postscript printer On Network PS LPT3 i PS File pxout nnn Enter Codes Current codes Enter lt RET gt to accept lt 5 gt to stop amp save all previous Alt F1 to cancel Character 4 1 0 LL f 12 4 2 PRN Mode Gray Map
223. mples per frame and number of resets per frame The number of images coadded for a single observation which gives what we call the integration time should not matter if the result is scaled by the number of coadds The pattern noise includes pixel and multiplexer channel voltage offsets in the array and in the signal processing electronics The pattern noise will depend on frame time because of the dark current It will also depend on the method and number of resets In general a single reset will not set each pixel to a hard reset value but will leave a residual depending on the flux level and the properties of that pixel To obtain a useful image it is necessary to subtract the pattern noise using an image with the same on chip exposure time For an optical CCD this is what is done when a dark slide exposure is obtained and subtracted from the sky image If there is substantial background flux in the sky image as is the case in the mid IR this will leave a pattern due to the gain variations from pixel to pixel resulting from differences in the detector in the array read out multiplexer and in the signal processing electronics To correct for this it is necessary to multiply by a gain map which we define to be the reciprocal of the relative gain for each pixel normalized to a mean of unity For the mid IR when beam switching is used with secondary chopping or telescope nodding the flux level and the camera settings will be the same in both
224. n or up and over shutter is moved across the aperture of the telescope If the camera beam is properly pointed at the secondary the traces will slowly rise as the telescope aperture views the thermal emission from the screen or shutter If the beam is completely off the secondary directly viewing the cold sky there will be no change until the beam is abruptly cut by the screen or shutter If the camera beam is completely off the secondary use the wind screen or shutter partially cutting the camera beam to locate the camera beam and adjust the appropriate dichroic dial to move the beam toward the secondary tracking it by moving the wind screen or shutter Step 2 IRTF With the dome shutter open and mirror cover closed open the mirror cover hatch Adjust the dichroics to align the beam on the secondary by maximizing the reflection by the secondary of warm radiation from the mirror cover The adjustments should be made so that the two traces and their ends are maximized together Step 2 UKIRT Follow the same procedure as the IRTF with the mirror covers closed There is no hatch to open since on UKIRT the mirror covers do not block the view from the instrument of the secondary and sky around it Step 2 S O 2 3 m With the mirror covers open partially close the shutter and wind screens to leave a small opening somewhat larger than the secondary to allow the sky to be viewed around the secondary Proceed as described for the IRTF Record t
225. n screen coordinates is in the upper left corner of the screen The typical VGA screen is 640 in the X direction and 480 in the Y direction The EGA screen is 640x350 The dimensions entered is the size of the plot box usually this should be smaller than the maximum screen 5 22 99 11 Reading Stored Data and Data Processing 89 size so that there is room for labels around the edges of the plot The log options can apply to either or both axes and only even decades are displayed If manually changing the X or Y data limits Autoscale is automatically turned off Labels of Plot This menu specifies the plot title the X and Y labels and how the tic marks are labeled Major tics are labeled minor tics are not Usually the major tic size is set to be twice the minor tic size The number of decimal places in the tic labels can be specified as well as the number of places to allow in front of the decimal If 0 0 is entered the labels are written in exponential format Contour plot levels The value of the contour levels can be manually set here If the auto contour level flag is set these levels are spaced evenly from the data minimum to the data maximum Gray level scaling The gray levels can be autoscaled or the levels set manually here These parameters also apply to the default image display Printer Setup This affects the printer parameters for the Hardcopy function described below This has no effect on the printer definitions available u
226. n the assembled spectrum of this star Suspected Var Var Hatzes amp Cochran 1998 A amp AS 128 207 detect long term radial velocity variations Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star Hammersley et al 1998 do not detect variability at mid ir wavelengths using IRTF and they include it in their new list of mid ir standards Suspected Var Var Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star Hatzes amp Cochran 1998 A amp AS 128 207 detect long term radial velocity variations Var Pulsating Var Larson et al 1999 ASP Conf series do not observe radial velocity variations on the order of 1 to 2 years for this star Within errors estimated to be 2 percent 3 percent at 20 microns Cohen et al 1995 do not detect variability in the assembled spectrum of this star 45 22 99 2 Standard IR Stars 113 Epsilon Mus Var Var Eta Sgr Var Var Gamma Aql Star in Double System Gama Cru Suspected Var Var Merdock et al 1992 MNRAS 254 27 detect periodic radial velocity variations for this star Gamma Dra Star in Double System Larson et al 1999 ASP Conf series do not observe radial velocity variations on the order of 1 to 2 years for this star IRC 10216 Possible PN Haniff 1998 A
227. name and path can also be entered in the MIRAC program and stored as part of the header file A list of the files required in the program directory is given in Appendix 11 MIRAC should be run from an observing directory which contains header mask gain flatfield command filter frame macro and plot parameter files This is in the O drove and is created for the particular observing run designated by the telescope month and year e g 5 0292 or G IRTF0692 Other default directories can be established for lab testing or other purposes such as O BILLTEST O JOETEST etc A list of the files required in the observing directory is given in Appendix 11 When MIRAC is executed it searches for a header file name on the command line For example MIRAC LABTEST where LABTEST HDR is a header file in the default directory If there is no command line parameter the program uses the CURRENT HDR file in the default directory This is the file that is automatically written when the program is exited It contains all of the program and camera parameters except the filter settings and camera magnification This file makes it easy to start the program again with all the same parameter settings when it was terminated If the CURRENT HDR file is not found the program stops displaying a message which explains how the program is to be run One can also type MIRAC INIT to start new without a header file If the program is terminated abnormally by a c
228. nd date are established there is a shorthand notation to designate a data file which consists of the index letter and the extension number This notation can be used anytime a range of names can be entered such as in the gain map calculation utility or the mosaic display function For example if a GRAB mode observation for the gain map has the file name C911203A 009 the shorter string a9 can be entered instead provided that the path and the remaining part of the file name is given by the data directory and the current DOS date or by a previously entered path and full file name If multiple files are desired they can be entered separated by commas or a hyphen used to specify all files between two extremes For example if the 4th 5th and 17th through the 23rd files are desired the following string is entered 4 5 17 23 Note that the zeros in the extension are not necessary and that the index letter must precede every number For example the string a17 23 is not valid In determining the file name based on the shorthand notation the program reconstructs a full path and filename using the numbers and letters provided and the default or previously entered directory and date For example the first time the user constructs a mosaic and wishes to combine the first 10 files plus files 23 31 from the night of March 17 1995 the necessary file range string would be C950317A 001 a10 a23 a31 Note that the first file name is written o
229. nder the PRN command line The printer selection resolution mode and size of plot have to be set Printer choices include Postscript printing to a file or to Ethernet The orientation portrait 1 or landscape 0 also must be set Usually landscape is chosen to make the plot as big as possible on the printed page Save Read files The current parameters in these menus can be saved to a file or read in from a previously existing file There is a default file for each plot type and the information can be saved to that file or a file name of the user s choosing 11 2 7 2 Redraw This function simply redraws the plot with the current parameters This is useful if the screen has become cluttered for some reason such as using the Level command described below or the Value command 11 2 7 3 Fit 1 D This option performs a least squares fit of a gaussian plus background or Moffat curve to the data currently being displayed The fit function is selected the DISP Init Statistics Fit menu The background has a constant linear and quadratic term The fit parameters are polynomial parameters b and c width parameter o peak value position and FWHM for the Moffat fit Once the fit is complete the fitted function can be plotted to the screen either using the same X intervals as the data or by using as small an X interval as possible The complete fitted function is plotted in light cyan and the background terms alone are pl
230. near the peak The files to be read in can be selected in two ways First a range of images can be entered by the user as a string in the usual shorthand notation The other way is to construct a DOS text file which contains file names of the images to combine In this second case the name of the DOS text file with the list of image file names is entered in the MOSAIC menu The images can be expanded as they are read in before adding them to the final image In this case the offsets are calculated to the nearest subpixel and the positioning of each individual image is more accurate Expanding the images also allows the program to properly adjust for the half pixel shift between the two halves of the array When the expansion factor is a multiple of 2 the halves are offset correctly before the maps are coadded The pixel at 1 1 is always the reference for the offset stored in the header The values assigned to the sub pixels can be determined by a weighted sum of neighboring pixels normalized for flux conservation default expansion or by a simple assignment of the original value scaled by the expansion factor to each of the subpixels force flat expansion As of the printing date of this manual the routine does not correct for optics distortion When the maps are combined the result is placed in the image display buffer The offset position 0 0 is placed in the center The final image size is then the limits of the good data after all th
231. ng If required command file must be turned on in Obs Next menu Start observation with F10 Savrdrun F6 Dispparm Sets display parameters to canonical values Section 5 2 Item 16 F7 F8 F9 F10 Savrdrun For standard star and program object to start observing with save and offsets Save on Read offsets on Run 7 5 Command Files The MIRAC3 program has the capability to execute a command file script that can be written to take a long series of observations The command file is a DOS ASCII text file that contains commands and macros one per line Comments can be put on any line after the semicolon character Arguments on a line are separated by spaces or tabs A command file is carried out by Run when Obs Next Use Command File is on Available commands are EM name execute the MIRAC macro with the filename name The macro file must be created and saved in the normal way The macro is executed as if starting from the OBS top command line The macro name should not include a file extension this is assumed to be MRM END end the command file This command must be the last command in a valid MIRAC command file FILTER cvf xx xx or name change filters to the given CVF wavelength or to the given filter name Both wheels are positioned correctly for the given filter or CVF position If setting the CVF one types FILTER CVF followed by the wavelength in microns between 7 68 and 14 5 If setting to one of the discre
232. nolulu office joseph hubble ifa hawaii edu IRTF secretary Karen Hughes hughes hubble ifa hawaii edu IRTF support scientist observatory superintendent Paul Jensen jensen herschel ifa hawaii edu UKIRT Observatory Arrangements Forms for UKIRT arrangements can be found on the UKIRT home page http www jach hawaii edu UKIRT home html Arrangements similar to those made for the IRTF should be made with Andy Adamson a adamson jach hawaii edu or the support scientist 3 3 IRTF Requirements List Example MIRAC Requirements IRTF Nov 7 23 1998 MIRAC team coverage Joe Hora Aditya Dayal and I will be covering the run with a gap the night of Nov 16 when Aditya will have just arrived Casey Lisse will be in charge of the camera that night Shipping MIRAC will be shipped from Tucson via FedEx Oct 27 to arrive in Hilo by Friday Oct 30 or Monday Nov 2 Unpack and setup This will be carried out Nov 4 Wed evening and Nov 5 Thu by Bill Hoffmann Massimo Marengo and Marc Kassis 16 MIRAC User s Manual Vacuum turbo pump This will be required Nov 4 Wed evening Liquid nitrogen Nov 5 Thu 12 liters cooldown Nov 6 23 4 liters day including boil off and transfer Total 72 1 Liquid helium Nov 5 Thu 10 liters cooldown 8 9 is typical Nov 6 23 5 liters day transfer only 5 is typical Total 100 1 transfer only Note In the lab MIRAC3 uses 8 liters for cooldown and 4 liters a day thereafter includ
233. o be read e g 44960406 Leave New Tar filename as If more than one directory is to be backed up press F4 and select the additional directories for the input path and for the output path Press F10 done to return to the Write Tar Tape Menu Press F10 done to continue In response to Warning press F1 Append after data on Tape In response to second Warning press F10 to continue When backup is finished press esc to exit program When in the main menu select Tape Utilities to obtain a summary of what is on the tape A21 2 Backing up Data with NovaBack on MIRAC PC DAT Drive NovaBack provides a local backup tape readable only by the PC It is useful for backing up the system and program files It is less useful for backing up data because of the lack of portability Locate current backup DAT tape Each DAT tape holds 2 Gbyte sufficient for all the data inarun reasonable approach is to use two tapes alternating adding the current and previous nights data to the tape Add to label current observing date Insert tape into ALR computer From DOS prompt novaback enter Using the down cursor key on the keyboard choose Select files for backup enter 236 MIRAC User s Manual Select drive volume with cursor arrows and enter D Select sub directories for backup e g d951202 with cursor arrows and spacebar To backup entire drive select the drive with spacebar Move to next menu with F10 key Cho
234. o large connectors Signal and Digital at the top of the cryostat one at a time and replace with the appropriate MS connector shorting caps Keep one hand on the cryostat to keep yourself grounded during this process Remove the other end of the digital cable from the electronics connector panel and set this short cable aside This requires a screwdriver 3 Remove the two smaller connectors Switch and Temp from the top of the cryostat Remove the other end of the Switch cable from the filter controller at the bottom of the electronics This requires a screwdriver 4 Remove the D connector at the base of the cryostat near the motors Remove the other end of this cable from the filter controller at the bottom of the electronics This requires a screwdriver 5 At the camera electronics disconnect the pair of fiber optical cables The coupling unit between cables should be left on the ends going into the camera electronics Put the small black protectors on the ends of the long cable and the large red protectors on the coupler ends Tuck the latter into the electronics box Remove the other ends of the fiber cable from the telescope fiber cable plate and install black protectors 6 Disconnect the 9 pin RS232 connector at the filter controller below the camera electronics This requires a screwdriver 7 Disconnect the MS connector Temperature Monitor at the electronics panel 8 Disconnect the AC power cord from the filter controller b
235. od observations or the off source pairs from chop nod observations form a standard deviation map Cut off the high noise pixels After editing the mask it should be saved in the observing default directory in the form O HNL1295 MSK The letters are H high N noise L low 76 MIRAC User s Manual 10 2 Gain Map Generation The function UTIL Functi Gain Map Calculation provides a convenient means for generating a gain map which we define to be the reciprocal of the relative pixel gains normalized to a mean of unity Thus the gain map must be multiplied times an image to flatten it The gain map calculation takes several images taken at two flux levels subtracts the average at one flux level from the average at the other finds the average of the difference and normalizes the map by dividing by that value and then inverts the map to generate the multiplicative gain map Mask Gain and Flat should be off during this calculation in order that the gain for all pixels be calculated After the gain is saved it can be renormalized for any particular mask The following are possible approaches to obtaining images at two flux levels The first is currently preferred 1 Dome and sky Set the frame time appropriate for dome images within the detector linear range With the dome closed and mirror covers open obtain 10 grab mode images at a 2 sec integration time With the same frame time repeat with the mirror covers open looking at the zenith
236. of the primary and the flux particularly at one side of the array should increase Record the read out values for each extreme at which either column 1 or column 2 increases an equal amount Set the control dial midway between Repeat for declination except for this case one or the other end of both traces should be most sensitive to moving off the primary This can be repeated for other chopper throws and the center values recorded for later use b Second Option adjust collimation midway between the two beams This is appropriate for small throw and when the source will be in both beams It also has the advantage that it should minimize chopper offset and pattern Repeat a except that for 200 MIRAC User s Manual one extreme of each adjustment the chopper should be in the on source position and for the other the off source position The chopper position can be changed using the IRTF chopper control in local mode or by redefining the off source beam in OBS Header Observe Nod and Chop Parameters Level of off source This is normally Zero so that level 1 in on source Changing this should switch the chopper position 2 Out of focus star image Run the camera chop mode current display at 2 2 um tracking a bright star Defocus the telescope to give a doughnut image This should be clear and symmetrical Adjust collimation to make it symmetrical This method is less sensitive and more ambiguous that method 1 since the appearance depends on
237. off and the sky and telescope background subtraction be carried out with Nod only In this case the symmetrical or four beam nod can be used with the sequence of 1 4 time off source half time on source and 1 4 time off source The nod only approach has the advantage of avoiding image smear due to chopper vibrations and the disadvantage of excess sky and detector noise because of the low frequency of telescope nod motion 5 22 99 Al Principles of Mid IR Observing 105 A1 3 Obtaining a Gain Map A gain map is obtained by observing two different levels of flux generally high flux in the closed dome and low flux on the sky This is preferable to using a dark or blanked off frame for the low flux since for the former case both flux levels traverse the telescope in the same way and any pattern over the array from telescope emission is the same for both levels and should subtract out Both flux levels must be observed with the same filter and frame rate This is discussed in detail in Chapter 10 1 4 Calibration of IR Images Flux calibration of the sources is performed by observing IR standard stars These stars are usually bright 100 Jy at 10 um so they require a short integration time to reach the same signal to noise as the sources of interest Since changes in sky transmission will compromise the accuracy of the calibration the standard stars should be observed as close as possible in time to the source Usually observations of a source
238. olumn output is desired the Auto functions must be turned off 2000 Scope Display 1500 1000 500 500 1000 1500 Col 10 Col 118 2000 10 20 30 50 60 70 9o 400 140 120 130 Row DISP 4 05 96 15 16 57 76 Data not saved SIMULATED STAR Mode Current Figure 12 1 Scope Utility Display The scope header values including camera parameters are separate from the current observing header since the values required for the scope usually are quite different from those used when observing They can be edited using the menu selection from the scope display Setup Edit Scope Header This is the same header edit menu as is accessible from the OBS command line except that 94 MIRAC User s Manual the filters cannot be changed here only from the OBS Header command There is also a command in the scope display menu to make the scope display header equal to the observe header This is useful when wanting to change only a few parameters from the normal observing settings Since the output level of the columns will likely be similar an offset can be entered for the second column displayed to separate it out from the first The two columns are also displayed in different screen colors If aligning the dichroic however an offset of zero is useful Then the user must simply try to adjust the mirror so that the output of the two columns are at an equal minimum If the scope Edit Scope Header Observing Parameters S
239. omatically sent to the camera with the next OBS RUN command Initialize Filters Obs Header Filters and Optics Init Filters yes lt esc gt This will issue the home command to each of the filter wheels in succession and turn off the motor current after the command is complete Listen or watch to make sure the filter wheels are turning If the wheels happen to be in the home position already the wheels will turn slightly as it moves away from the home position a small amount and then returns to home For subsequent camera power ups during the run the Init Filters command is not necessary since the filter positions are stored to a file However the Init Filters command may be executed at any time and should be run if there is any doubt as to the current position of the filters The home position is filter wheel 1 8 8 um filter wheel 2 open Prepare Chopper drive Turn on facility chopper electronics Set direction normally 0 north Set throw normally 10 to 60 arcsec Set nod throw usually 20 60 arcsec E W Request operator to set throw IRTF and S O 90 Inch Set throw in Obs Telescope Telescope Control Nod Beam Control UKIRT Set the telescope nod vector is described in Section A14 14 For moving objects planets edit catalog if necessary for changing position from previous day In menu Obs Header Source Information enter object with new position and Put current source list From Dos prompt edit catalog to delete previo
240. ompass directions can be displayed as an option These directions plus the selection of X and Y flips and Transpose determine the orientation of the data on the screen and as written to FITS files Section 12 5 62 MIRAC User s Manual The statistics for the data being displayed are shown below the grayscale image The maximum minimum average standard deviation rms and number of the unmasked pixels are calculated all in ADU Analog to Digital Units maximum 2047 minimum 2048 These numbers are for the portion of the image chosen in DISP Init Stats Display Region for Stats generally Full excluding masked pixels The maximum unmasked value found in the selected region is assumed to belong to the source in the image The position of the source is determined by calculating the centroid of a small region surrounding the maximum value pixel If the fit option is on the peak full width half maximum FWHM and chi n 1 of a Gaussian or Moffat fit to the source are calculated Also the data and fit are displayed as a radial profile plot in the lower right corner of the screen and the FWHM value added to the plot at the left The source sum is calculated as the sum of the values minus the mean background level in all pixels around the maximum which are closer than N FWHM pixels to the source where N is the Inclusion width factor entered in the DISP Init Stats and FIT menu The average standard deviation and number of pixels are
241. on Nod Wait off 000000000 Jomerwoit 000000000 Telescope Focus 0000 Time Check UT Time MIRAC W F H 12 13 94 4 Page Date UT MIRAC LOG WORKSHEET W F H 12 13 94 5 MIRAC LOG OBSERVING Date UT Page File No Obs Time Object Wave Frame Int Mode Chop Offset Cmd Sky Obj Air Comments purpose chop throw nod throw Run UT um msec sec G C N Hz File off File cmd Flux FWHM Mass noise sig focus sky temp humidity image quality 130 MIRAC User s Manual 5 22 99 7 mrc2fits Program 131 Appendix 7 mrc2fts Program The program mrc2fts c converts raw data files from MIRAC format to FITS The compiled C program can be obtained from the MIRAC home page on the WWW Section 2 1 It performs the same function as the UTIL Functi Fits File Output command does in the MIRAC PC program but the mrc2fts program is a stand alone C program that will run on a Sun workstation and eliminates the need for a PC to perform the conversion The individual images in the observation will be subtracted 1 for data in the chop nod mode bad pixels can be masked and gain map applied To compile the program several other files besides mrc2fts c are needed All of these files plus a Makefile are included in the software release which is available vi anonymous ftp from hubble ifa hawaii edu in pub hora mrcreduce called mrc2fts
242. on file list output to a list It has taken th added the two The files ataul17 The size of the filenames in the original ffsets the final image and final image is Note that with lcoadproc This procedure assumes that to zero 142 User s Manual 5 22 99 All Files Necessary for Program 143 Appendix 11 Files Necessary for MIRAC Program Files that must be in C MIRAC LOADDSP BAT loads dsp program MIRAC BAT sets DOS default directory to observing directory and starts MIRAC PRNTINIT BAT runs LOADFONT to load gray scale GRAY 12 SFP into printer RTMRUN BAT installs PC NFS Resident Transport Module needed at IRTF EGAVGA BGI graphics driver SVGA256 BGI DSP DAT MOSAIC DAT weight file for mosaic expansion PRINTERS DAT printer definition file for MIRAC program MIRAC DSP dsp program BEAM EXE INITCOM EXE LOADFONT EXE loads softfonts to printers MIRAC3 EXE executable program OFFSET EXE RTM EXE real time program necessary for running DPMI programs RTMREM EXE removes PC NFS RTM resident program TCSINFO EXE MIRAC FIL saves the current filter positions GRAYI2 L2D DPMI16BI OVL 16 bit protected mode driver GRAY 12 SFP soft font for HP laserprinter TELRS232 TFD Files that should be in C MIRAC not essential but useful TMONITOR DAT temperature sensor calibration LOADFONT DOC AIRMASS EXE used for calculating and print
243. or the LHe transfer Transfer LN2 Remove the LN2 vent cap from the LN2 fill fitting Insert LN2 short funnel with valve rod lightly inserted into outer fill hole Fill with LN2 from 4 flask until LN2 spatters out Insert valve rod remove funnel and return excess to 4 flask The 2 7 liter LN2 reservoir holds about 3 5 funnels full Top off should require about 2 5 funnels full Restore LN2 vent cap to the LN2 fill fitting Transfer LHe a b 4 Remove LHe safety vent cap from the LHe fill fitting Move LHe storage dewar into position for the transfer Insert flexible transfer line into storage dewar to coodown the transfer line Avoid too high a pressure Support the transfer line to that it is about 1 inch above the bottom of the storage dewar to avoid getting into sludge The fitting at the top of the storage dewar has a teflon O ring which does not provide enough friction to support the transfer line When the tip of the transfer line is cold dripping liquid air insert slowly into MIRAC center fill hole Pause at 7 inch depth for about 10 seconds first black mark on the fill tube in order to fully cool the end of the transfer line to Then insert another two inches second black mark for the remainder of the transfer This approach will avoid blowing out the LHe remaining in the cryostat at the beginning of the fill The transfer should take about 5 minutes When suddenly the plume become
244. ose yes for verify tape Move to next menu with F10 key Choose Add to Tape for tape already containing files and Overwrite if new tape is being used enter When finished press esc to exit the program A21 3 Backing up Data on a Unix Computer If the data has been written to a unix computer such as bok at the SO 2 3 m telescope or planck at the IRTF it can be backed up to data grade exabyte tapes such as Sony 112M 8 mm tape cassettes or by 4 mm computer grade DAT tapes if a DAT drive is available on the Unix computer Each Exabyte cassette holds approximately 2 5 GB of data At the 2 3 m telescope the exabyte tape drive is the leftmost drive located in the computer cabinet to the left of the observer s console At the IRTF the drive is located at HP in the computer room The backup routine is the standard unix tape archival procedure tar This should be available on any unix computer A21 3 1 Basic Unix Tar Commands In lieu of the predefined macros the following unix commands can be used The name of the tape drive stl for the IRTF and device name rst1 should be marked on the unit To avoid an automatic rewind start the device name with n nrst1 allocate stl to allocate the tape drive tar cvf dev rstl writes entire current directory and subdirectories to a tar file on the tape overwriting any previous information on the tape tar xvf dev rstl directory name recovers files from the tar tape writing the
245. otted with a red dashed line The fit equations for the Gaussian are 90 MIRAC User s Manual y a bx cx FWHM 2 354 6 For the Moffat fit there is an additional parameter p which is set in DISP Init Stats X a bx cx 1 MT y Yo L ae Where 11 2 7 4 Value This command creates a cursor that the user can move over the plot to show the value of pixels on the display As the cursor is moved the location and value are printed in the lower left corner of the plot The delete key toggles the cursor fast motion mode In this mode the cursor moves 10 screen pixel steps per keystroke rather than the default 1 pixel step per key Pressing any key other than the arrow or delete key will return control to the top command line In the 2 D mode the value displayed is based on the X Y position of the cursor In the 1 D mode the value reported is the Y value based on the current X position In this mode the Y position of the cursor is not relevant 11 2 7 5 Level 2 D Contour only The level command will draw a new contour level on the plot at the value of the current cursor position cursor is positioned in the same way as the Value command and then when RETURNe is pressed the position is selected and the contour drawn 5 22 99 11 Reading Stored Data and Data Processing 91 11 2 7 6 Hardcopy The Hardcopy option is no longer implemented in MIRAC3 To get a hardcopy of the graphics
246. ound based telescopes presents many unique problems The main difficulties result from the fact that the sky and the telescope emit strongly at these wavelengths This background is generally 10 to 10 times stronger than the source In addition this background is constantly changing from drifts in the telescope temperature and rapid fluctuations in the sky emission on time scales as rapid as a few hertz While these fluctuations are largely correlated over the field of the array there is a residual that creates noise in the image Also in many arrays there is a low frequency current noise which is uncorrelated from pixel to pixel To remove the effects of the background emission separate images of the source and nearby sky are obtained with beam switching by chopping and nodding the telescope Rapid beam switching with a square wave motion of the telescope secondary mirror is done to modulate the source signal at a frequency of a few hertz above the frequency of the dominate sky and detector fluctuations Additional slow beam switching is carried out by moving the telescope nodding at a frequency of a few hundredths of a hertz to remove the effects on the image from the different telescope collimation in the two chop beams The beam throw in both cases is generally set to the array field size or large enough to assure that the off source beams are truly off the source if it is extended or if there are multiple sources in the field Typically c
247. ow or column to calculate the frequency spectrum of the data assuming each pixel is spaced in time by the pixel time specified by the camera parameters 11 2 5 Histogram This mode constructs a histogram of the values in a row column or the entire display buffer and plots them in a 1 D plot similar to the SLICE mode The bins are selected as a percentage of the total range of the image data This is shown in Figure 11 4 5 22 99 11 Reading Stored Data and Data Processing 87 Opt ions Setup Redraw Value Hardco Output EEJ Exit 2000 Npix 15709 1800 1600 1400 1200 1000 600 400 200 Gaussian Fit Peak 1 897E 3 Xpos 5 0 1697 FWHM 8 0778 Const 1 819 Linear 1 505E 1 Quadr i a rm 3 ChiSar 5 370E 3 OBS 4 05 96 15 31 04 c960405a 001 SIMULATED STA IDLE 0 00 0 02 0 5 DISP 4 05 96 15 16 57 76 Data not saved SIMULATED STAR Mode Current Figure 11 4 Histogram Display 11 2 6 Radial Plot The Radial Plot mode is illustrated in Figure 11 5 This plot is similar to the calculation done in the array display mode Figure 9 1 except that the full screen is used and the hardcopy and other plotting commands are possible The center of the source is determined by calculating the centroid for a region near the peak value in the image and then the distance from the center is calculated for every point A small cross is drawn for every data point and the best fit function drawn through the points
248. ple differencing The methods of loading data are controlled from the DISP Load menu For previously saved data the data is loaded using this menu For data coming from the current operation this menu controls how the image is processed with mask gain and flat field matrices before it is displayed If the program is in the ARRAY display mode as determined in the DISP Init menu then the current contents of the image display buffer is always shown in the main image display screen Different methods of display such as Contour or Slice are initiated in the DISP Begin menu The mode of display is selected and the function is executed from that menu 11 1 Methods of Loading Data When the DISP Load Load command is issued the data is loaded using one of the following formats These formats must be selected using the DISP Load Mode option before the Load command is used The default directory for reading data is initially the same as the data file directory where new images are being saved However if a new path is entered for a data file that directory becomes the new default directory for reading data 11 1 1 Current Observation This is the mode most useful when observing It displays the most recent observation taken The automatic masking gain and flat field operations can be activated to improve the image If the Observation is a combination of images 1 in chop or nod mode all off source and sky subtractions are done automa
249. pliers Tape measure 10 feet 3 meters Thickness gauge Caliper inches and cm Brush with rubber ball Rouge sandpaper Loose parts small plastic container Small plastic round container Hardware and electronics plastic box Rubber gloves for cryostat disassembly Coax BNC cable 4 ft Test leads with banana plug ends 4 long 4 medium Ziplock bags 1 qt and 1 gal Alcohol Propanol 125 ml plastic bottle Plastic container with cover 118 ml Battery spare 4 5 V alkaline for level sensor Battery spare 1 5 V AA alkaline for flashlight 2 Battery spare 9 0 V alkaline for Fluke meters 2 Wire stranded heavy Wire twisted pair 20 feet Wire twisted pair 24 feet with banana jacks Envelop of spare resistors and capacitors Q tips Breathing mask Antistatic envelop CONTINUED CRATE 8 SUPPORT EQUIPMENT CONTINUED 3 of 4 Loose items small plastic container Computer supplies plastic box Spare A D converter Detector input test circuit Short ribbon cable Data command termination cable BNC cable Clip leads BNC Banana adaptors Candle Spare cryostat window Electric carving knife usually not needed not packed Pair of blades for carving knife usually not needed not packed Fluke meter with double banana leads Magnifying visor Spare screws plastic box Electronics test kit box Fuses 7 and 5 amp slo blo for power supply IC clips 6 Short test leads with various pins Controller board pin test leads Banana test probes with pointed ends 2 Banana
250. plotting in the DISP Begin menu The settings for the grayscale autoscaling also control the scaling of the main image display screen 11 2 2 Contour This mode will display a contour image of the data in the image display buffer This is illustrated in Figure 11 2 The number of levels is set in the contour parameters menu in DISP BEGIN and the contour levels can be chosen manually or selected by the computer automatically The automatic selection evenly spaces the levels between the minimum and maximum values 5 22 99 11 Reading Stored Data and Data Processing 85 Opt ions Setup Redraw Hardco Exit 130 120 110 60 50 40 20 10 72 59 5 O 40 20 30 40 50 60 70 80 90 100 110 120 130 0 2818 MIRAC2 U of Arizona Smithsonian Ast Obs OBS 4 05 96 15 26 21 c960405a 001 SIMULATED STAR IDLE 0 00 0 02 0 5 DISP 4 05 96 15 16 57 76 Data not saved SIMULATED STAR Mode Current Figure 11 2 Contour Display Mode Additional levels can be drawn after the plot is complete by using the Level command The cursor is positioned to the desired location and a contour level is drawn based on the value at that pixel location The position and value of the data is displayed on the screen as one moves the cursor to aid in selecting the level 11 2 3 Slice The SLICE mode displays a 1 D plot along either a row or column of the array The SLICE mode is illustrated in Figure 11 3 The direction is always from dat
251. pose and comparing the CVF scan with a Beckman Acculab Dual Beam Spectrophotometer scan through the same sample This scan and previous calibrations are in Supercalc and Microsoft Excel spread sheet files in the MIRAC computer CVF directory The most recent calibrations are shown in Figure A3 3 The steps for calibrating the CVF are 1 Source and sample setup Locate a thermal radiation source incandescent lamp about 1 or 2 feet in front of the cryostat window Using a ring stand and clamp support a 6 x 6 inch piece of cardboard mask with a hole smaller than the clear aperture of the Beckman polystyrene sample about 2 inches from the cryostat window centered on it With another ring stand and clamp support the Beckman polystyrene sample on the radiation source side of the cardboard so that the sample can easily be slid out without disturbing the cardboard Have available a third piece of cardboard to use as a room temperature source 5 22 99 A3 MIRAC Filter Data 117 2 Camera setup OBS Next Wavelength CVF 11 75 Integration Time 2 Frame Time 8 4 Chop Nod Mode Grab Save off How many Obs per run 2 Read offset file off Use command file off Link frame filter off OBS Header Filter Precise Step inc5 Run To confirm that for this frame time the peak flux at 11 75 without the sample is within the linear flux level Change frame time if necessary OBS Mode Step CVF on OBS Next Save on How many Obs per run 200 3 Data taking
252. r xv f drive file 7 Printing 7 1 The Printer Queue List the Queue 1 Removing Printer Job lprm job Removing Your Printer Jobs lprm Selecting a Printer lpr Pprinter Pprinter Pprinter job 7 2 Printing troff Output and Screen Dumps troff Output 1 t Screen Dumps screendump rastrepl lpr v 234 MIRAC User s Manual 5 22 99 21 Tape Backup 235 Appendix 21 Tape Backup A21 1 Backing up Data with NovaTar on MIRAC PC DAT Drive NovaTar provides a backup tape in Unix Tar format so that it can be read on a Unix computer with a DAT tape drive It is most suitable for the data backup The MIRAC PC contains convenient batch files for tape handling WRITE READ LIST REWIND Executing any of the first three without parameters provides an explanation The procedure for using these commands is given in Section 6 2 Alternatively it is possible to use the NovaTar menu driven approach as follows Locate current backup DAT tape Each DAT tape holds 2 Gbyte sufficient for all the data inarun reasonable approach is to use two tapes alternating adding the current and previous nights data to the tape Add to label current observing date Insert tape into ALR computer From DOS prompt novatar enter tape enter also will start novatar Using the down cursor key on the keyboard choose Write Tar Tape enter Using tab and cursor keys edit DOS filename to first directory t
253. r gt enter 7 14 Printing Images MIRAC images can be printed on a local HP Laserjet or Deskjet printer or postscript network printer or to a postscript file Printing is accomplished by executing PRN Print Yes or the macro Fl The desired printer is selected in PRN Init and the Mode in PRN Mode Printing to a local printer uses a downloaded grayscale character set Post script printing uses a postscript gray scale Printer Timings are given in Table 7 4 The best approach during observing is to print to a file in the observing directory and when there is time at the DOS prompt netprint the file from MIRAC to the network printer 5 22 99 7 Observing Procedures and Check Lists Table 7 4 Printer Timings HP Laserjet 13 Postscript to network printer using LPT2 35 Postscript to MIRAC disk file 4 5 Postscript to mounted facility disk 30 Copy PS file from MIRAC to mounted disk 4 Copy PS file from MIRAC to network printer 45 Net Print PS file from MIRAC 6 seconds 51 52 MIRAC User s Manual 5 22 99 8 Short Form Instructions 53 8 Short Form Instructions for Running MIRAC Using the MIRAC Program Created by Sarah Stewart 12 7 95 Revised 11 18 1998 JLH 8 1 General Notes 8 1 1 Getting around in MIRAC lt esc gt takes you back to command line main menu lt page up gt take you back up one menu first letter of menu line will execute that option otherwise use arrow key to select and press lt enter g
254. rameters Liquid nitrogen shield temperature determined by a Lakeshore Cryogenics diode mounted on the LN2 shield near the reservoir If the electronics and A D temperatures are out of range they can be adjusted by increasing or decreasing the cooling air circulation by removing the electronics side cover plate or by covering the ventilation holes with cardboard The cardboard covering the board access inside the electronics enclosure should always be in place to insure proper flow of cooling air The temperature controller normally comes on when the camera power switch is turned on regulating the array at the temperature set by the multiturn potentiometer at the controller The dial temperature calibration is given in Table A14 3 Table A14 3 Temperature Controller Dial Dial 35 78 125 151 181 212 277 344 411 478 543 Temp 4 0 4 4 4 8 5 02 5 30 5 5 6 6 5 7 0 7 5 8 0 Dial 605 663 718 770 819 864 908 949 988 1025 Temp 8 5 9 0 9 5 10 0 10 5 11 0 11 5 12 0 12 5 13 0 The controller modes of operation are determined by two toggle switches Switch 1 Local The temperature controller operates whenever the temperature monitor power switch is on Remote The temperature controller operates only when the camera power switch is on Switch 2 Manual dial determines directly the voltage going to the detector stage heater Auto The dial determines the temp
255. rash it tries to save the current parameters into CRASH HDR Within each directory there can be several copies of different header files used for different tasks For example one could have a file that stores the parameters to use for observing with the broad band filters and another header file with parameters to use for observing with the CVF Parameters from past observing runs can be kept for quick reference 60 MIRAC User s Manual The data files are normally stored in the disk drives D and G using subdirectory names such as D960405 9 3 Data File Name Conventions The camera images can be saved to disk and or displayed to the default screen All images saved to disk are written to files with a name derived by the PC in a format that includes the current date and picture number The first letter in the file name is a C followed by the last two digits of the year then the month and day followed by an index letter for a total of 8 characters The file extension is composed of the image number which runs from 000 999 For example the 5th image taken on the night of August 23 1991 would be saved to the following file C910823A 005 After reaching the 999th file the index letter A would change to B and the 1000th file would be C910823B 000 When reading files the directory in the OBS Init Save Directory and the current date are assumed unless a path and file name with a different date are entered the directory a
256. rce and obtain several observations of blank sky at the same integration and frame time as for the source observations The flat field can also be constructed from the off source images from several chop or chop nod observations In either case the average of these observations should be saved in the 5 22 99 10 Mask Gain and Flat Field Maps 77 observing directory to file with a name that identifies the wavelength and date such as O 1171008 FLT 10 4 Using the Mask Gain and Flat Field maps The user can choose to automatically use the Mask Gain and Flat Field maps when displaying data The data written to disk from the camera is always directly from the camera using these automatic files only changes how the data is displayed To have the program use Mask Gain and Flat maps turn on the appropriate item in the DISP Load Auto menu and enter the desired file name 10 5 Principles of Mid Infrared Flat Fielding Flat fielding with a mid infrared camera is straight forward in concept and theory although sometimes difficult in practice It is different from flat fielding in the near infrared and also is sometimes confused by imprecise or differing uses of vocabulary Each image has what can be called zero flux pattern noise that is the image obtained by observing with zero flux on the array with the same camera settings as are used for imaging namely on chip integration time which we call frame time readout speed number of A D sa
257. rd Stars with Magnitudes in Alphabetical Order 3 8 0 2 0 71 1 86 3 12 3 15 1 43 1 4 1 36 0 68 3 73 1 3 1 36 4 5 4 2 3 3 05 2 05 2 02 1 2 1 22 2 45 2 47 1 6 1 7 0 76 3 33 1 4 3 5 1 75 2 3 0 95 1 46 4 8 0 2 0 6 1 92 2 96 2 93 1 44 1 36 1 36 0 68 3 4 1 16 1 12 0 0 4 16 3 9 2 8 2 77 1 8 1 78 1 12 1 09 2 2 2 2 1 3 1 4 0 62 3 05 1 2 4 4 1 41 2 1 0 7 1 4 Wavelength um Magnitudes 7 9 0 0 78 1 9 3 08 1 45 1 37 0 68 3 8 1 24 4 75 4 4 2 95 2 1 22 2 45 1 5 1 57 0 7 3 14 1 3 72 1 65 2 7 0 87 1 6 8 8 0 0 78 1 9 3 16 3 12 3 14 1 45 1 38 1 35 0 68 3 85 1 24 1 25 0 0 4 75 4 4 2 98 2 95 2 97 2 1 96 1 98 1 22 1 21 1 23 2 45 2 37 2 44 1 5 1 61 0 7 0 73 3 36 1 3 7 2 1 65 3 3 0 93 1 6 9 8 0 0 75 1 9 3 13 3 18 1 5 1 39 0 7 3 88 1 31 0 5 1 4 5 3 3 06 2 05 2 07 1 19 1 24 2 51 2 5 1 73 1 7 0 78 0 8 3 37 1 44 7 6 1 73 4 2 0 95 1 6 10 3 0 0 75 1 9 3 15 3 19 1 5 1 39 0 7 3 93 1 3 0 5 2 4 5 3 01 3 08 2 07 2 1 1 19 1 25 2 51 2 53 1 72 1 7 0 78 0 82 3 38 1 45 7 6 1 74 4 3 0 96 1 6 N 3 14 1 35 1 31 3 02 2
258. ript time is anumber up to 4 digits script is the name of a file containing the command line s to perform 5 Users Seeing Who Is Logged In who 5 22 99 Changing Identities su username Seeing Your User Name whoami who ami who is this 6 Managing Files 6 1 Looking Up Files Standard Commands whereis filename Aliases and Commands Describe Command Searching Out Files which command whatis filename find dir name name print dir is a directory name within which to search name is a filename to search for 62 Tracking Changes Comparing Files diff leftfile rightfile diff prefixes a left angle bracket lt to selected lines from leftfile and a right angle bracket gt to lines from rightfile Auditing Changes Putting Files Under sccs Checking Files Out Checking Files In Backing Files Out Recovering Current Versions Reviewing Pending Changes 6 3 Automating Tasks Create a Makefile mkdir SCCS chmod 775 SCCS sccs create filename rm sccs edit filename sccs delget filename sccs unedit filename sccs get SCCS sccs diffs filename vi Makefile A makefile consists of macro definitions and targets Test Makefile Run make make n target make target A20 VMS DOS UNIX Command Reference 233 6 4 Managing Disk Usage Seeing Disk Usage df du s du sort r n Ls l Making A Tape Archive tar cv f drive file Extracting Archived Files ta
259. rol of the Telescope Another method of control is to send the telescope control computer direct commands via an RS 232 link Drivers have been implemented for the 2 3 m SO and UKIRT telescope control systems This is the preferred method since it allows other commands besides the nod to be sent The connection 5 22 99 9 Using Program 73 necessary to use this method is RS 232 cable from the COM port of the to the telescope computer input in the control room A special cable has been made for this purpose to interface correctly between the RS 232 port on the PC controlled by the MIRAC program to the telescope computer input For the nod beam control the wobble vector must be input before the command is sent This generally must be done once at the beginning of the night Then the current position must be defined as beam 1 When the Beam2 command is sent by the MIRAC computer or the Wobble box the telescope computer will command the telescope to move to the current position plus the wobble vector Then when the Beam command is sent the telescope is moved to the current position minus the wobble vector In this way the telescope alternates between the beam 1 and beam 2 positions Note that the positioning is not absolute so that if two Beam 2 commands are issued the telescope will offset twice as far as the Beam 2 position Using the RS 232 commands gives the user additional command options Telescope parameters
260. round wire 12 feet blue UKIRT Nylon cord plastic container Kim wipes small box LN flask 4 liter white Ethafoam spacer LN and LHe insulating foam vent tubes Electronics box and cryostat sled Ethafoam Velcro cable straps board with 2 long 7 medium 3 short with buckles CRATE 4 POWER SUPPLY Gray Duct Tape 12 26 21 81 Ibs 05 22 99 Camera electronics power supply in plastic bag CRATE 5 COMPUTER Yellow Fiberglass 28x28x16h 107 Ibs 05 22 99 Analog digital I O interface Mouse Plustec PC computer in plastic bag with attached BNC cable and optical fiber cable Keyboard in plastic bag AC power strip for computer 4 feet with 4 foot extension Do not disconnect extension Computer power AC cord Monitor power AC cord Ethernet cable 15 feet RTF or 4 feet S O 2 3 m usually not needed not packed Ribbon cable 50 pin for A D Digital I O 5 5 feet Blank DAT tapes box of 4 Blank 3 5 inch floppy disks box of 6 Backup 3 1 2 inch floppy disks System boot disk root util batch directories DAT programs Dos directory 3 disks parts 1 2 3 NFS directory MIRAC program and observe directories Jupiter Tracker II Galsat 52 Filter motor controller test programs Computer assembly tools and parts plastic parts box Sharpie colored amp black pens fine and extra fine points Grease pencil Magic marker Screwdriver 1 8 blade Phillips screwdriver 1 8 blade Razor blades 2 Pen light Scotch magic tape Elastic bands End covers
261. rray 1 0 3 3 C Init ROW subarray 1 0 3 0 A 71 gus D End ROW subarray 1 0 3 3 B 1 43 ps Bandwidth Time Constant 71 ps Go 52286418 Detector Bias 2 000 Dis 4071 us Reorder data into image On 11 5 ps H Offset Values gt 22 7 ps Frame time filter links gt G 90 9 ps J Skip bad images in DSP On H 14 ms Offset Frame time filter 1 A Low flux offset 1572 00 Read Frame times file Sky frm B Medium flux offset 3368 00 Save Frame times fil Sky frm C High flux offset 6058 00 Edit filter frame times D Variable offset 0 00 CVF frame time values E Fixed Linear Max 5180 00 Jj F High Dark 660 00 G Full Well 7508 00 p Edit Frame time values msec A 2 2 16 140 00 3 8L 16 140 00 4 8 16 70 00 D 7 9 4 39 00 8 8 10 35200 9 8 10 20 00 G 10 3 10 20 00 10 6N 8 1 13 1 pm 6 60 I 11 7 10 20 00 J 12 5 10 22 00 K 17 400 2 6 31 00 17 801 2 6 31 00 18 005 10 9 00 20 603 6 8 15 00 5 22 99 12 1 OBS Command Line Menus and Site Mauna Kea IRTF 1 870 19 8261 155 4708 r Edit CVF Wavelengths and fry ror TA Telesco A Wlth 7 600 39 00 E B With 8 00
262. rray single read rms read noise preamp input 27 digital units 082 mV array input 853 electrons Array electron gain times dispersion DG 1 96 Array saturation level 2 29 Volts 2 36x10 electrons 7400 digital units Linear range 1 65 107 electrons 5170 digital units Array background for BLIP noise 3 x read 3 4x10 electrons 1065 digital units 5 23 99 2 Overview Performance 9 2 6 Background Sensitivity Noise The sensitivity and integration times for the MIRAC3 set of filters on a variety of telescopes can be obtained from the MIRAC home page Section 2 1 Electronics and Computer MIRAC3 sensitivity calculator The sensitivity and noise of MIRAC3 is determined from observation of standard stars and blank sky Several chop nod sets are taken with the standard star at different positions on the array These images are mosaiced with offsets determined by centroiding star signal in digital units is calculated as the sum of the source for all pixels above a noise threshold The background noise is given by the standard deviation over the array of chop nod sets taken off the source The measurements agree closely with the sensitivity and noise determined by calculation from the detector camera filter telescope and sky properties The total background is the flux entering the camera from any source The sensitivity for the IRTF 3 m is given in Table 2 4 The surface brightness sensitivity is given first s
263. rrect The user is prompted for the RA DEC EPOCH and observatory r nl n2 specifies a range of images 1 2 to be processed with one command With this option is necessary to only to give the root name of the file on the command line The file numbers are appended to this Example Files 1950709 455 to 532 taken on July 9 1995 are to be corrected with a factor of 0 2 The following command is used aircor 950709 0 2 r 455 532 5 22 99 9 MIRAC Image Header File Format 135 Appendix 9 MIRAC Image and Header File Format A MIRAC format observation file consists of a header of 32768 bytes and an image of 128 x 128 4 byte integers for each of the observation sky subtraction beams Thus the file size for a grab chop and chop nod observation are 98304 163840 and 294912 bytes respectively The data are ordered by image column The header has a flexible format which allows easy additions or deletions The following is an example of a header from November 15 1998 given in FITS format SIMPLE T DATA IS IN FITS FORMAT BLIPLX 32 BITS PER PIXEL lt 0 REAL NAXIS 2 NUMBER OF AXES NAXIS1 128 PIXELS ON 1ST MOST VARYING AXIS NAXIS2 128 PIXELS ON 2ND MOST VARYING AXIS BSCALE 1 000000000000e 00 VALUE DATA BSCALE BZERO BZERO 0 000000000000e 00
264. rs Shut down camera and MIRAC program Turn off Camera Power and Temperature Monitor switches Quit MIRAC program with Quit Yes Copy log to data directories e g 36 5 MIRAC User s Manual From DOS prompt for current observing directory e g o irtf1295 copy 12 02 95 log d d951202 enter copy 12 02 95 log 134951202 enter Initiate MIRAC DAT NovaTar tape backup NovaTar provides a backup tape in Unix Tar format so that it can be read on a Unix computer with a DAT tape drive It is most suitable for the data backup Instructions for an alternative backup using NovaBack are given in Appendix 21 The standard backup procedure is to maintain two backup tapes Tape A and Tape B alternating them each night backing up both the previous nights and current nights data files Each DAT tape holds 2 Gbyte sufficient for all the data in a run Label the tapes with MIRAC Telescope and Run dates and Tape A or B The PC contains convenient batch files for tape handling WRITE READ LIST REWIND Executing any of the first three without parameters provides an explanation 6 7 8 9 10 11 Locate appropriate tape A or B Add to the box label the names of the last and current nights directories Insert tape into ALR computer From DOS prompt for example write 4 d d960415 d d960416 The number 4 in this example is the number of tar files data directories to skip before writing the new ones It is
265. ry host computer bok planck etc The time zone for the clock UT local is selected in an NFS setup menu and is set automatically by TIMES UT must be used for the observations This is necessary for the proper calculation of airmass for the observations It also insures that the data files will all have the same date for a single night of observing Create an observing directory for the run in the O drive It should be designated by the telescope month and year e g enter 6 7 8 9 5 22 99 5 Start and End of Run Setup and Shutdown Check Lists 23 mkdir o irtf0696 enter As a start copy all files needed from O OBSDIR or the previous run s observing directory into the new These will include header mask gain flatfield macro command frametime plot parameter log offset and object catalog files Old log and other files specific to the run can be deleted from the new directory A complete list of the required files is given in Appendix 11 The new observing directory is the directory from which MIRAC will be run Edit the MIRAC BAT file in the C MIRAC directory to set the new observing directory name selected in item 2 as CURDIR to set the network real time interface RTMSTAT on for IRTF off for other telescopes and to set PRNTON to on if there is a printer attached directly to the PC and off if there is not Use the DOS command EDIT MIRAC BAT The RTM program is the Resident Transport Modu
266. s 5 22 99 20 VMS DOS UNIX Command Reference 229 simple One filename or directory 4 Editing Files name to access local file or directory Type vi to enter text editor then any of following absolute List of directory names from root commands in command mode unless preceded by a directory first to desired filename or directory name each name separated by to add text relative List of directory names from cc to substitute a line with a string enters insert current position to desired mode filename or directory naem each name separated by 2 12 Directory Abbreviation Home directory username Another user s home directory Working directory Parent of working directory 3 Commands 31 Date and Time Type date For universal time Greenwich Mean Time type date u 3 2 Calendar Type cal year for yearly calendar cal month number year for monthly calendar 3 3 Wild Cards Single character wild card Arbitrary number of characters 3 4 Redirecting Output System types output of command to file rather than screen replacing current contents of file if any Type command name filename System types output of command to file rather than screen appending to current contents of file if any Type command name gt gt filename 3 5 Basic Calculator Type bc to enter interactive program Type arithmetic expressions using and symbols followed by RETURN To change number
267. s 05 22 99 Camera electronics box with attached filter controller with foam support cryostat temperature sensor heater cable 4 feet inside electronics box signal input test connector connected to signal input inside box at top Filter home switch cable Filter motor drive cable Digital bias cable with filter capacitor box 3 feet Filter controller AC cord Cryogenics Kit Tygon tubing 3 8 ID 3 long LN extraction fitting Copper 1 4 diameter 14 long for warming cryostat LHe slitted vent tube Bunsen spare Cryogenic level sensor LHe supply dewar O ring fittings 2 Tygon tubing 1 2 ID 34 long w coil spring for LN removal Tygon tubing 1 4 ID 89 long Tygon tubing 1 4 ID 60 long Tygon tubing 1 2 ID 24 long Tygon tubing 1 2 ID 18 long Tygon tubing 1 2 ID 6 long Soft rubber surgical tubing LN funnel long with tube protecting rod LN FUNNEL short with tube protecting rod Tygon tubing 1 2 ID 38 long Bladder for LHe transfer with 3 8 ID tubing 6 long Cryogenic gloves pair Safety goggles CRATE 3 CABLES Yellow Fiberglass 18x34x22h 163 165 05 22 99 Cable bundle 120 feet Connector protective sheaths both ends Power with dummy protective connectors on each end Temperature monitor Filter controller RS232 AC Power for filter controller power supply 100 feet at control room end Camera end goes in first with 8 feet free wrapped around outside of crate Filter controller AC cord 10 feet G
268. s etc These factors could lead to an over or underestimate of the PSF depending on the conditions For example if the telescope drifts significantly during a 2 minute total elapsed time integration on the source but drifts very little during a 10 second integration of the standard the effective PSF width of the camera for the source will be much higher than the star observations show On the other hand if 40 integrations are taken on source but only 5 standard star observations are taken because of the high S N on the bright star then the shape of the stellar profile will not be as well sampled as the source Usually the sources of interest are fairly faint and one wants to maximize the integration time spent on these and minimize time necessary for calibration We have found that a good compromise is to take 15 20 fairly short around 5 sec on source exposures of the standard star before and after taking no more than 30 to 40 30 second on source observations of the source If more source observations 106 MIRAC User s Manual are needed this is repeated as many times as necessary observing the standard star between each set of source observations This sequence must be repeated for every filter and or CVF position used 45 22 99 2 Standard IR Stars 107 Appendix 2 Standard Mid IR Stars A2 1 Standard Star Tables The following tables give a selected list of standard mid IR calibration stars The tables include some stars which ar
269. s have the advantage they make the measurement at the same flux level as the astronomical observations hence are not so sensitive to array non linearity But they suffer from small signal and great sensitivity to changing sky conditions It is even possible to get negative gain map elements with those methods Also they can be affected by changing flexure between the telescope and the camera optics and array with changing telescope orientation The third method gives large signal to noise in the difference is least sensitive to sky vagaries and is most reliable However care must be taken to chose the frame time so the dome flux is within the linear range of the array and is similar to the level the array is operated at during astronomical observations This will be shorter that the frame time used for the astronomical observations because of the higher flux from the closed dome With burst mode readout of the camera where the readout is a fixed time and the frame time is determined by a delay between readouts this difference in frame time has little effect on the gain properties of the array This is not likely to be the case for continues readout for which the frame time is changed by changing the read time The linear range is not in general the same as the A D range For the Rockwell HF 16 the linear range goes from the zero flux level to about 69 of full well In any case it is essential that the zero flux pattern noise be the same for both
270. s in the DISP Init menu allow selecting the orientation of the image display and the direction marker the type of monitor and turning on or off the Magnified and FWHM displays The most useful display selections are Heat SVGA and Default VGA Force B amp W on The monitor must be in Default VGA Force B W off to print graphics screens with the PrntScrn key or with Word Perfect Grab The image can be displayed with binned pixels by setting Factor for VGA Bin greater than 1 Arcsec Grid Display permits turning on an arcsec grid image overlay and selection the spacing and color of the grid 9 7 Setting Camera Parameters and Taking Data The camera parameters are set in either OBS Next or OBS Header Observe Filter or Hardware The most frequently changed parameters such as the frame time and filters are gathered together in OBS Next The parameters effecting the camera electronics timing are not immediately sent to the 5 22 99 9 Using Program 67 camera in order to avoid changes while images are being obtained They are sent either when Camera Init is executed or if Camera Init has not been executed at the next Run command In the latter case the camera will pause before starting the observation Data taking is initiated by executing OBS Run This can be done in simulate mode without the camera OBS Init Simulate on or with the simulator off and the camera attached and running Save can be on or off Log should always b
271. s of objects for offset and airmass calculations The catalog files are used by the program AIRMASS to generate lists of airmasses for objects OBSLIST can also create a text file e g PN1292 TXT for printing out the catalog The MIRAC directory contains the WordPerfect file CATALOG WPW to format this text file for a HP Laser printer The following information is stored for each object the RA and DEC the proper motion in RA and Dec the object type and the object name It is best to use all capital letters in order not to confuse other programs that read the data from these files We have used the TYPE field for storing a 3 letter code for the type of object This is compatible with the Steward Observatory telescope software and old pre 5 89 versions of the CATALOG program by Dave Harvey Newer versions of the CATALOG program use the TYPE field for magnitude so if one desires to use this program one must generate a special file using the t option described below The following types have been defined STD Standard Star QSO Quasi Stellar Object SAO SAO catalog star HII Region PN Planetary nebula DSH Dust shell around star PPN ProtoPlanetary nebulaAGN Active galaxy nucleus SFR Star forming region YSO Young stellar object GAL Galaxy SBG StarBurst Galaxy MCD Molecular Cloud Currently only the STD and SAO types are recognized by the program All others are regarded as Targets The output is sent to
272. s the dome images Also take one set of image at each frame time in the blank wavelength position Wait a minute after each filter change The procedures for Mask Gain and Flat Maps are discussed in detail in Chapter 10 7 3 Wavelengths Frame Times Frame Filter Link Files and Filter Change Times It is most efficient to select filter sequences which minimize the filter change times These depend on whether one or both filter wheels must be changed and the amount of motion for each The wheel for each filter is indicated in the OBS Next Wavelength menu The filter change times are given in Table 7 2 5 22 99 7 Observing Procedures and Check Lists 41 Table 7 1 IRTF Typical Frame Times msec Wavelength Wheel Sky Dome 2 2 2 70 70 3 8 2 70 70 4 8 2 70 60 7 9 1 50 35 8 8 1 35 6 6 9 8 1 20 4 4 10 3 1 20 4 4 10 6N 1 6 6 1 1 11 7 1 20 4 4 12 5 1 20 4 4 17 4 2 39 20 17 8 2 31 20 18 2 4 4 2 2 20 6 1 8 7 6 6 8 8 1 70 20 10 1 70 20 CVF 13 5 1 35 20 Blank 2 Measurement settings Magnification 5 2 3 m 33 pixel 43 IRTF 41 pixel 34 UKIRT 41 pixel 27 MMT 56 pixel 27 Bandwidth 71 usec Burst Mode Read time 2 2 msec The frame times are chosen for background within linear range and noise background shot noise Nominal frame times for keeping the sky flux within the linear range for the filters are given in Table 7 1 These are chosen so that the sky flux is less than the max
273. s to be nonlinear The frame time should be chosen so that the sky flux plus the data or fit max for chop or chop nod is less than this value The frame time and the level of flux should be chosen so that the outofrange pixels hi low should be 0 0 FrameErrors is the number of chop cycles in the observation found to have one or more data transmission errors and dropped from the observation if OBS Header Hardware Skip Bad Images is on When each data word is loaded into a FIFO memory to be transmitted from the camera to the DSP in the MIRAC computer the three lowest order bits are duplicated into three high order 5 22 99 9 Using Program 63 positions not required for the data The DSP compares these for each data word and rejects the current chop pair if an error is detected The sky linear max is calculated by sky l x fixed dark 1 4 rounded to three significant figures where Sky sky linear max spread FWHM of the responsivity relative to the mean 15 fixed fixed linear max where the array starts to become nonlinear 5180 frame selected frame time dark value for the dark current for the 10th highest pixel x y integrated over 17 5 msec frame time 660 For a frame time of 8 7 msec the sky linear max is 4580 For 17 5 msec it is 4260 for 35 msec 3640 for 70 msec 2400 and for 131 msec 220 Hence for this array 131 msec is the longest frame time t
274. s very strong release the storage dewar pressure remove the transfer line and close the storage dewar top valve Restore the LHe safety vent cap to the LHe fill fitting The LHe safety cap should be on the LHe vent at all times except during transfer to prevent air entering the LHe fill line causing an air ice plug Replace MIRAC on telescope 204 MIRAC User s Manual a Position cart with MIRAC next to guider box The clamping screws should be fully withdrawn b Raise cart so that ball on mounting plate is just above cradle Push MIRAC and slide slowly into place so that ball is over cradle and tongue is in slot c Gently lower table until ball seats in cradle and mounting plate screws are alined with their holes Screw in mounting screws and tighten with allen wrench 6 Stow the cart 5 22 99 16 Checking and Trouble Shooting 205 Appendix 16 Checking and Trouble Shooting A16 1 Software or Digital Logic Lockup in PC DSP or Camera A possible although rare occurrence is a digital or software lockup in the camera or digital signal processor In the former case imaging should be aborted the camera power supply cycled off and on and the system reinitialized In the latter case the PC power should be cycled A digital lockup in the PC can prevent the monitor from displaying If this happens it is necessary to cycle the power on the PC using the switch at the back or the power plug leaving if off for several minutes A16 2
275. scope 4 Disconnect cables from control room at camera 5 Disconnect signal and clock cables at cryostat and put conduction caps on cryostat connectors 13 Depart Turn off dome most of control room and corridor lights Lock door Exit 38 MIRAC User s Manual 5 22 99 7 Observing Procedures and Check Lists 39 7 Observing Procedures and Check Lists 7 1 Check List for each Set of Observations Most Mirac operations during observing can be carried out from the OBS Next menu For each set of observations check the items in this menu 1 5 6 7 8 9 Object Name Names in the Source Catalog OBS Header Source Information List of sources will automatically enter the RA and Dec from the Source Catalog These are used for the Air Mass calculation and go into the image file headers Non catalog entries Sky Dome will give a message not in catalog The positions of objects not in catalog such as planets or comets can be entered in current epoch in the Source information menu and if desired added to the Source Catalog If there are multiple entries with the same object name only the first will be used for positions Wavelength Integration time Level of flux set in OBS Header Normally medium Set to low for low flux 2 2 um blank measurements or sky observations with dome frame times Use display out of range number of pixels as a guide Chop frequency set in OBS Header This should be set to the de
276. screen one can use the GRAB COM program or some other TSR program to save a copy of the screen to disk in some standard format then later print it out The other option is to hit Shift PrtScr to do a graphics dump to the printer GRAPHICS COM which is required for this is normally loaded when the computer is booted The monitor must be in Default VGA mode for a graphics print 11 2 7 7 Output 1 D The Output function allows the user to write an ASCII file containing the X and Y data that is currently being plotted The data are written in exponential format in two columns separated by a comma These files can then be imported into other programs such as SuperCalc5 or other spreadsheet programs for further analysis and display 92 MIRAC User s Manual 5 22 99 12 Utilities 93 12 Utilities The MIRAC utility functions are grouped in a separate command line directory UTIL Several of the available options are discussed below 12 1 Scope Display The main purpose of this display is to provide a rapid refresh analog display of the output from the camera It can be useful when aligning the dichroic at the beginning of the run The data are displayed in a line plot with up to 2 columns displayed at once This is illustrated in Figure 12 1 The Scope display is a real time data display mode and images are not saved to disk even if Save All is turned on The gain mask and flat field functions however do apply so if the raw c
277. ses for the standard stars in the sources cat file for March 13 1993 on Mauna Kea with 3 columns per page airmass sources cat 12 24 1992 r 23 11 t sources ams this outputs to the file sources ams the airmass listings for the targets for the UT range 23 hours to 11 hours on Dec 24 25 1992 at Kitt Peak This program was written in C for a PC based on the Fortran program SHOWAIR FOR It was later modified to compile on a SUN To compile this program on a PC using Microsoft C compiler version 5 use the following statement cpl F 9000 airmass c On a Sun use the following command airmass c lm o airmass The size of the arrays set in the program below can be changed to increase the number of sources allowed using the parameter MAXSRC in the program In the case of the PC the stack size may also have to be increased the F parameter above For other systems some tweaking may be necessary but the program uses fairly standard C so it should not be a big problem 5 22 99 Manual Log 125 Appendix 6 Manual Log It is important that all sheets be numbered sequentially for the entire run The cryostat sheets should be kept together at the beginning and numbered alphabetically e g 1 1b 1c The first few pages of the log are likely to be Cryogenics la 1b Worksheet 2 Setup 3 Worksheet 4 Observing 5 There should be a new setup sheet for each night of the run The log sheets can be photo copied double
278. sformation from pixel to sky offsets depends on the telescope plate scale the camera magnification the object being Observed since the R A offsets must be put in seconds of time for the Steward telescopes and the data array flips and directions defined in the DISP Init Options menu Therefore when commanding telescope offsets it is important to display the direction indicator on the default screen and to insure that it indicates the proper direction of the data array The program can be directed to ask the user for offsets The selection is in the OBS Mode menu When this flag is set whenever the OBS RUN command is entered the offsets menu automatically pops up to ask the user for the desired offsets When exiting the menu the observation is started If the offsets were changed the offset command is sent to the telescope otherwise the integration is started without offsetting A sequence for an observation could be as follows the user hits OBS Run and the program asks for offsets Offsets are entered and the offset menu exited The program looks at the offsets entered and decides whether any offsets need to be sent to the telescope If necessary the program encodes the offset values and sends the commands to the telescope to set the offset values Then the command to move to the current position plus offsets is sent to the telescope The program then waits for a specified time for the command to be executed and the telescope to stabiliz
279. short Allen ball L wrench 050 long Allen ball driver 050 Allen L wrench 032 Cardboard optics baffle cover cardboard detector cover Dentists mirror Detector shorting plugs 2 Shrink tube for gaseous nitrogen cleaning Soft brush small Brush 1 inch Toothpicks Filter wheel disassembly parts box wheel 1 2 and 3 diagrams Empty compartments with tissue for filters Cardboard masks for filter protection Copper rings 3 8 and 5 8 spares Electronics parts box 1 MMM Super77 Adhesive for foam usually not needed not packed Electronics tools and supplies plastic box Elco crimp tool Cannon crimp tool Solder sucker Elco pins Cannon pins small Copper solder wicking wire Shrink tubing short piece Wire wrap wire assorted colors Lengths of wire 4 pieces Wire stripper and screw cutter Elco extraction tool Cannon extraction tool Cannon insertion tool Wire wrap tool IC removal tool Wire stripper large Electrical tape CONTINUED CRATE 8 SUPPORT EQUIPMENT CONTINUED 2 of 4 Mechanical tools plastic box Tin snips Allen ball handle wrench 3 16 Allen ball handle wrench 5 32 long Allen ball handle wrench 9 64 Screwdriver 1 8 blade 1 Screwdriver 1 4 blade Screwdriver Phillips small Screwdriver Phillips medium Jeweler s screwdriver 1 16 inch Round file Crescent wrench No 6 missing Allen wrench L set 050 to 5 16 Scissors Sharp nosed pliers 2 Wire cutters 2 Exacto knife and blades Automobile
280. should be the same for the entire night and similar from night to night Rapid changes in atmospheric conditions such as changes in humidity will affect the extinction and may make more frequent monitoring necessary Also the extinction is dependent on the wavelength so the value must be determined for each filter used The extinction value is determined from observations of an object at two different airmasses Usually observations of a standard star are used since the S N is high and one frequently observes the star at different airmasses during the normal course of observations The determination of the extinction is more accurate if there is a large difference in airmass for example from 1 0 to 2 0 and it is usually a good idea to average the results from several stars The extinction value is given by the following relation 2 3 d log C C og C C 8 1 where ADU of source at low airmass ADU of source at high airmass A Low airmass value A High airmass value Once the extinction value is decided on the aircor program can be used to correct the data for atmospheric extinction This program reads in FITS data files and applies the correction based on the airmass value in the header and the supplied extinction value For an observation at airmass A the corrected value P is calculated from the observed value P using the following relation e A 1 10 22 8 2 134 MIRAC User s
281. sired value which is stored in the program The actual chop frequency is calculated to be the closest to the desired value for each selected frame time Frame time This is set so that the sky flux is nearly as great but not greater than the LinMax shown on the display and no high out of range pixels A table of wavelengths with frame times for both sky and dome is provided in Section 7 3 When Link Frame Filter is the frame time is automatically set for the selected filter according to the selected frm file Chop Nod mode Save on off How many observations per run This is the number per offset position typically 2 For non saved observations such as finding a star or focusing this can be set high e g 50 or 1000 10 Read offset file on off name of file ifon Offset files are described in Section 7 6 11 Use command fileon off name of file if on Command files are described in Section 7 5 The time taken for various filter changes is given in Section 7 3 12 Link Frame Filter on off name of file if on Frame files are discussed in Section 7 3 13 Zero current position to make sure that offsets run correctly 14 Check chop and nod throw Sections 14 12 and 14 14 40 7 2 1 2 3 4 5 6 7 MIRAC User s Manual Check List for a Nights Observations First star acquisition generally at wavelength 2 2 um either IR standard star or Yale bright star catalog Mirac parameters are set with t
282. t 8 1 2 Rebooting lt ctrl alt delete gt soft reboots need to check the startup parameters after reboot check current observation number so data is not overwritten 8 1 3 Stopping a run while taking data W ait E nd 8 1 4 Getting around in DOS mkdir creates a directory rmdir deletes a directory del deletes a file changes to the drive changes directories 8 1 5 To get back to MIRAC from DOS ret or return or Make sure you are in o irtfMMYY directory Type exit at the DOS prompt 8 2 Starting MIRAC 8 2 1 Prep Work Set up log sheets Fill cryogens normally done by operator at end of observing night Check that LN2 slide at camera is OPEN 54 MIRAC User s Manual 8 2 2 Turn on computer amp set up directories In DOS Create data directories check disk space available Check the c nfs drives bat file to make sure IRTF network drives are mounted properly If not edit c nfs irtfdriv bat to reflect directory paths in the network Then copy irtfdriv bat to drives bat Then reboot the computer rem means remark comment line in the bat file 8 2 3 Start MIRAC Start program type mirac at prompt to start the program A batch file automatically sets the directory to o irttfMMYY where MMYY is the month of your run 8 2 4 Check detector temperature Turn on temp switch left switch on the MIRAC power supply The det temp should read 3 7K Mauna Kea 4 3K sea level If
283. t 40 and last 25 rows are removed from each image Pixel column 1 row 1 is located at the o on the display The example is given for initial images 128x128 pixels Larger images can be loaded in Processed Mode but they must be trimmed to 128x128 in the following steps At each step of trimming the image size must be maintained at 128x128 neither larger or smaller The partial images are placed in the first through fourth quadrants of the display in clockwise direction Disp Load Load filel operation or processed mode Header Source Image Initial Col 504 1251 Initial Row 40 1241 End Col 50 128 178 End Row 40 128 2 168 Util Arith Justify X Hlip Y Flip Disp Header Source Image Initial Col 65 1 66 Initial Row 65 1 66 End Col 65 128 193 End Row 65 128 193 Util Arith Justify X Flip At this point the partial image is in the third quadrant Y Flip To move to the first quadrant Disp Header Source Image Initial Col 65 1 66 Initial Row 65 1 66 End Col 65 128 193 End Row 65 128 193 Disp Save Current partiall 5 22 99 11 Reading Stored Data and Data Processing 83 Repeat for file2 file3 and file 4 moving to quadrants 2 3 4 and combine to four images Disp Load Load partiall partial2 partial3 partial4 operation mode Disp Save Current combined 11 1 7 Processed Images Previously stored maps can be read from the disks The files can be in the default MIRAC format or FI
284. t chapters is of the form OBS Header Observe Chop Frequency where each item separated by is executed by a single key stroke the first letter of the item in either upper or lower case The first item is the command line Subsequent items are menus or selections within a menu A parameter such as Chop Frequency above is entered with enter Page up moves one menu back up esc returns to the command line Alt F1 exits the menu canceling the changes that have been made It is also possible to move through the command line and menus with the cursor arrow keys MIRAC menu switches are turned on and off with y yes or n no When MIRAC is terminated by Quit all current parameter values are saved in current hdr which is loaded when MIRAC is next run 6 1 Nightly Startup Tasks The filled circle indicates tasks which must be carried our for each startup The open circle indicates items which should be checked each startup A bar 1 after either indicates items that can be accomplished at anytime after the previous nights observing For the first night the Start of Run Setup Tasks Section 5 2 which include the nightly setup should be carried out 1 Clip new Observing and Setup log sheets from MIRAC3 Log Sheets Notebook onto MIRAC clipboard Enter telescope date etc on Setup sheet Enter additional items as you proceed Use last night s setup sheet as an example 2 Check detector temperature at MIRAC PC computer Turn on AL
285. te filters one types FILTER followed by the name Below are the valid names 2 2K 11 7 3 8L 12 5 4 8M 17 4Q0 7 9Me 17 801 8 8 18 005 9 8 20 6Q3 10 3 CVFxx xx 10 6N BLANK INITCAM Send the current header parameters to the camera equivalent to the OBS Init Camera Init command 44 MIRAC User s Manual LOADHEAD name read the given MIRACS settings file header file This is useful for restoring a particular camera configuration OFFSET ra dec change the telescope offsets to the given ra and dec values in arcsec These are performed when the next RUN command is done PAUSE ss ss Pause for the given number of seconds RUN execute OBS Run command to start taking data The program will wait until this run is complete before executing the next command line Note that one Run command can actually be many observations if for example the program is also using an offset file NWRun same as RUN except it doesnt wait for the observation to complete before moving on to the next command This is useful when wanting to do something like start a run then go and print out the last observation Can be used in conjunction with the WAIT command to again start waiting WAIT Causes the PC to wait until the current observation is complete until the next line of the command file is executed Can be used in conjunction with NWRUN to execute other commands while data is being taken Having a NWRUN followed by a WAIT is equal to doing a
286. ted button screws from the base of the radiation shield and lift off the shield A19 6 Removing the upper section of LHe radiation shield 1 This requires removing the two heat sinking and radiation stopping clamps from the ribbon cables and releasing the tape holding the cables to the radiation shield 226 MIRAC User s Manual A19 7 Reassembling Cryostat This is done by reversing the above steps The bottom plate on the LN shield will have to be removed from the shield in order to align the actuators during reassembly Remove the slotted 3 16 inch 4 40 slotted screws from around the edge and two 1 8 inch 2 56 screws at the LN slide mechanism Lift off the bottom and set aside taking care to avoid damage to the actuator rods When reassembling the bottom care must be taken to align the two filter wheel actuator spades with the slots on the LHE base The LN slide mechanism should be aligned and the two 2 56 screws installed before inserting the screws around the edge of the bottom plates The bottom of the radiation shield with the charcoal sieve should be baked out overnight in a vacuum at about 60C Each radiation shield should be installed wearing gloves and rocking shield gently while pushing down take care to align the holes screws should go in without binding If a screw binds do not force it Leave it out Use MIRAC cryostat assembly collars to prevent shield screws from falling into the cryostat When reversing Sect
287. tem 5 e 6 Prepare data directories Create today s data directories and check memory available in MIRAC computer and facility computer at DOS prompt Entries below are as an example d enter mkdir d951202 enter UT date for start of observing dir enter to check that entry is correct 1 enter cross mounted on facility computer mkdir d951202 dir enter to check that entry is correct If either directory has less than 200 Mbytes available then either try another drive g in MIRAC or j on facility computer or delete old data directories Note on IRTF the following is the usual drive i scrl data mirac If running DOS shell within MIRAC execute ret lt enter gt NOTE ret automatically executes o and exit It is necessary to always return to the o drive before exiting from the dos shell to MIRAC Enter names of data directories in MIRAC program again using the above directory names Obs Init Data file directory d d951202 enter Backup data directory 134951202 enter esc O 7 Prepare Command Macro Offset and Frame Time Files as Required Standard macro offset and frame time files are in the Observing directory New ones if required should be prepared prior to the observing time but sometimes must be edited during observing They are described in Chapter 7 o 8 Enter source catalog name Obs Header Source Information List of sources e g backspace jupiter cat enter esc
288. tes which level will be the resting position between integrations and which beam is subtracted from the other This is important on the SO 1 5 m telescope because the two beams differ in image quality The chop mode is illustrated in Figure 9 3 9 9 1 3 Chop Nod This mode takes two sets of chopped images one in the Beam 1 position and the other in the Beam 2 position as defined by the telescope control computer for a total of 4 images This is shown in Figure 9 4 The mode is selected by setting the Grab Chop switch to CHOP and setting the Nod selection to 2 beam nod The source is assumed to be in the On Source chopper beam of the first chopped pair and the other 3 beams are assumed to be of blank sky Therefore the image 5 22 99 9 Using MIRAC Program 69 arithmetic for the two chop sets containing images I1 12 13 14 where contains the source is 11 12 13 14 Figure 9 5 shows the chop nod mode with the source in all four beams Chop Beam 2 Chop Beam 1 On source Figure 9 3 Sky Modulation in the Chop Data Taking Mode Chop Beam 2 1 1 2 lt gt Figure 9 4 Sky Modulation in the Chop Nod Data Taking Mode 70 MIRAC User s Manual Chop Beam 2 Chop Chop Beam 1 Nod Beam 1 Nod Beam 2 lt 6 69 Figure 9 5 Sky Modulation with source in a
289. th vs step to bring the CVF and Spectrophotometer scans of the 9 725 and 11 03 um absorption lines From one cryostat disassembly and reassembly to another the scale should not change at all and the start value by no more than 05 um The values determined November 13 1998 are Scale 5 455822 x 107 um step CVF start 38225 steps 7 239 um Steps Revolution 53333 MIRAC CVF CALIBRATION 500 400 3 5 300 s E 2 E 8 200E E 100 E 9 725 um W E GuruLLLEELELELELLELEELELEELLELELEELEEEEEEEEEEEELEEEEEEEELELEEEEEEEELELEELISNL LLLI 7 8 9 10 Ti 12 13 14 15 Wavelength microns CVF 7 09 94 CVF 5 24 95 Beckman Hi res Fit Beckman Low res 5 24 95 CVF Step 3058 14 640 um 0 0068727 um step Figure A3 3 CVF Calibration July 9 1994 and May 24 1995 5 22 99 4 OBSLIST Program 119 Appendix 4 OBSLIST Program The program OBSLIST EXE and its C source code OBSLIST C are in the C MIRAC directory on the MIRAC PC The compiled C program can also be obtained from the MIRAC home page on the WWW Section 2 1 purpose of OBSLIST is to create and manipulate source list files ALL CAT YSO CAT etc These are the files that the telescope control program reads to obtain the coordinates of an object for pointing the telescope and the MIRAC program reads to obtain the coordinate
290. the floor at the east side of the pier to the yoke and thence to the mirror cell support At the IRTF it is routed around the telescope chamber wall hanging from the mezzanine to the west end of the telescope yoke It follows an IRTF white cable from a support point on the mezzanine with a slack loop to telescope yoke Then if follows snugly along the yoke to a point near the MIM where it again follows the IRTF white cable in a slack loop to the corner of the MIM where is snugly routed along the MIM structure to the South West corner of the MIM Then it is routed back without support to the electronics where it is firmly strapped across the top edge with three velcro straps allowing about 3 feet for a loop to the connectors At UKIRT the cable is hung from the telescope chamber wall near the control room to keep it off the often wet floor and thence routed on the floor to the instrument area of the telescope The short fiber cable sections in the computer crate have adequate length for UKIRT The routing of the cables at the IRTF is shown in Figures 14 7 and 14 8 5 22 99 14 Hardware Preparation and Setup 189 Figure A14 7 IRTF Cable Routing at the telescope Note that in the bottom figure the cable loop from the telescope yoke is incorrectly hung up on the corner of the MIM It should drop to 26 inches above the lowered platform Also the loop from the camera to the MIM should drop 40 inches below the MIM In the upper left figure t
291. the guider box TV and MIRAC 5 22 99 7 Observing Procedures and Check Lists 49 7 9 Final Telescope Focusing Step 1 Focusing in the infrared Set the camera as in Section 7 8 Optimize focus for best appearance and fit FWHM Step 2 TV focusing At the IRTF the relay optics mirror should be in the low mag position The relay lens should be approximately in the center of its range use a 1 4 inch allen wrench to loosen the large screw under the relay optics assembly Slide the TV on the mounting shelf to obtain best focus At the 5 0 2 3 m the TV should be mounted with no spacers Put the relay optics mirror in the high mag position Then adjust the position of the relay lens loosening the large screw under the optics assembly to provide the best image 7 10 Autoguiding at IRTF 7 11 Autoguiding at UKIRT 7 12 Observing Times Setup First Clear Night 25 hr Adjust guide TV pupil position and focus This can be done in daylight with the dome open or at night with the dome lights on 25 hr Adjust dichroic mirror This can be done either in daylight or at night with the dome open or closed 25hr Initial visible bright star acquisition and focus This must be done in twilight or darkness This is a major task only with Steward Observatory telescopes Shr Set chopper throw with visible star This requires darkness 25hr IR focus Adjust TV relay optics focus at camera if necessary Locate IR center on TV screen 15 Set nod b
292. the standard output usually the screen To send the output to a file so that it can be printed use the redirection symbol on the command line in DOS or UNIX examples are given below The source list is used in the MIRAC program and the telescope control computer Each telescope has a different format requirement and in some cases a specific filename extension The extensions used are MIRAC cat no requirement on extension Steward Obs cat required extension irt requirement UH 88 inch uha no requirement 120 MIRAC User s Manual UKIRT dat required extension A number of command line options are available Sources may be added deleted inserted and sorted The source list can be sent to a different output file and the source list can be printed Various modes are available for entering and deleting the sources The available functions are explained below The form of the command is obslist sourcefile a ra dec pmra pmdec type epoch objname d n TYP i n q 1 r n1 n2 o outlist s t x telescopefile p TYP m otherlist f path where sourcefile sources list old Steward format Optional command line switches add source to list The RA and DEC are in the usual format hour and degree format e g 21 14 23 423 pmra and pmdec are the proper motions in sec century and arcsec century type is the object type epoch refers to the RA and DEC coordinates and ob
293. ther program such as a spreadsheet program There are two types of information that can be output The first outputs a single column of numbers from a range of images and the second outputs specific quantities from a range of images at one line per image For the column data output either a single frame in the observation can be printed to the file or the data after subtracting the off source images The output file is ASCII with the numbers separated by spaces For the second type there are three choices Temperature for which time in seconds from the beginning of the day detector temperature A D temperature and heater voltage are given Sky Flux for which observation number wavelength sky flux sky rms and sky difference are given and Error For error the digital signal processor checks for word slippage in the data transmitted from the camera to the PC displays the number of chop cycles with one or more errors in FrameErrors to the right on the Main Screen and saves the errors for each observation in the observation file header errors for a set of files can be listed with UTIL Functi Output ASCII Type of Data Output Errors For each observation and array channel the number of errors is printed for each chop half cycle 12 5 FITS File Output The FITS output utility takes the observation files and writes a FITS format file that can be read in using other data processing systems such as IRAF The utility reads the observ
294. they would not be positive integers to 1 files files into IRAF using file 212 as the reference the results in and storing e containing th first two columns pixels They may not in with the IRAF file names Type the file made by makelist file and replaced the necessary for lcoad Coadd data to make final image ataull7 sg4 the sigma map tion offsets of numbers in the files Also note that the maxi this indicates that t with an are created calculated from the input file sizes and offsets the input image sizes need not be the same all bad pixels have been fixed or set equal Look at the image that was created by lcoadproc offsets determin Compare this example sinc 141 Also may want to and negative for taken out by this method valid data value should the data is using imstat the pixels from the mask image bad pixels expanding by 4 and using the gain Here we are using an extinction value of 0 2 rocess For all good files move the cursor over The script constructs a file list with the these should not be used when pk200 list to a format that the xcor program will need the first character instead of the i that smoothing both atauoffs d by peak_eval these to should match the previous ones up to within a I was not too careful when mum correlation value is he cross correlation was ati
295. tic box Tools and screws for mounting and for removal for cryogen transfers are in the Camera Assembly plastic box Figure 414 5 shows the camera mounted with the MIRAC guider box The following steps should be taken to install the camera at the telescope The Camera electronics connector positions are given in Figures 14 6 and 14 7 1 Mount the bolt circle adapter flange with SO 1 5 m telescope bolt circle on the telescope mounting flange This is usually done by the telescope staff 2 Remove the top cover plate and mount the guider box on the telescope using 6 1 2 12 x 1 25 screws with washers and a 3 8 allen wrench The cryostat side should face south The guider box can be raised into position with an adjustable height table or with the platform elevator 186 MIRAC User s Manual 3 This item is no longer done Remove the TV cover plate on guider box and mount the observatory guiding TV camera using a 5 32 ball driver S O For the IRTF mount the TV shelf to the guider box and the IRTF TV camera on the shelf with a 1 4 20 socket head screw The TV face should be xxx inches from the guider box face 4 Note Item 4 and 5 can be done in either order Item 5 can be carried out in advance of item 4 on a rolling cart in the control room Remove the cryostat cover plate on the guider box and window cover on the cryostat and mount the cryostat The cryostat mates to the guider box with a self aligning ball and tongue Tighten the
296. tically to produce a single display image All of the data can still be saved to disk in its original form these automatic calculations only affect the data displayed When this mode is selected the image is displayed in the main image display screen after receiving it from the camera The data is then in the image display buffer It can then be displayed from the DISP BEGIN menu with any of the other options such as contour image or one dimensional SLICES through the image It can also be saved as a processed file When the next observation is 80 MIRAC User s Manual complete it replaces the data that is currently in the map display buffer and it is displayed in the main image screen 11 1 2 Accumulated Observation This mode is similar to the Current Observation mode except that when the new observation is complete it does not replace the current data but is coadded to the current data This mode is useful when several images are taken of an object in the same position The signal to noise ratio would continue to improve in the displayed image with each additional observation In practice this mode is rarely used since there are always small drifts and offsets between each image for long integrations which would misalign the successive observations 11 1 3 Replay Mode The Replay display mode will display a range of images in the main image display screen It is useful for scanning quickly through a set of images when processing the
297. ting up the computer Other tasks should be done before leaving for the mountain to save setup time for the first night 4 1 Object Lists and Air Mass Charts It is useful to have lists of the target objects plus SAO reference stars and flux calibration standards entered in computer files in the proper format for MIRAC and for the telescope control computer This saves time in moving between objects since all the telescope operator must do is to type in the object number instead of the complete R A Dec proper motions etc and reduces the risk of making errors when typing in the information Another useful observing resource is a printed list of each object and its airmass for various times throughout the night This aids in planning the night of observing since one can see when each object will be observable There are two utility programs which perform these operations OBSLIST Observing LIST and AIRMASS Both are in the MIRAC program directory in the DOS version and in the UNIX subdirectory in the UNIX version These programs are described in detail in Appendices 4 and 5 The program OBSLIST is used to create manipulate and print lists of observing sources The files used by OBSLIST are of the form CAT These files are used by the MIRAC program and OBSLIST can also produce special versions required for the S O telescopes CAT the IRTF IRT and U of Hawaii telescopes UHA and UKIRT DAT The and UKIRT files can b
298. tion of the display options and parameters setting 15 given in Section 9 6 9 5 Using MIRAC Menus and Functions The MIRAC program utilizes a pull down menu system similar to many other PC programs complete listing of the menus is given in Appendix 12 The top command line of the main screen has a number of menu choices as shown in Figure 9 1 These can be selected by moving the highlight bar using the left and right arrow keys to the desired choice and pressing ENTER or the down arrow Using the HOME key moves the highlight bar all the way to the left and the END key moves the bar all the way to the right The top menu choice can also be selected by typing the command character for that choice There is command character for each option on the command line menu denoted by the highlighted or underlined character in the word character is the first unique character that specifies the command usually the first letter Starting a top line command either executes a function opens a pull down submenu with other choices or goes to another command line items in upper case In text mode overlapping submenus are displayed on the screen In graphics mode there is a single submenu area in the center of the screen Options in this submenu can change parameters perform functions or lead to further submenus When the choice leads to another menu a right arrow character is displayed on the right side of the menu across from that sele
299. tire object The approach is to offset the telescope by small increments usually by a few arcsec for each set of 2 or so observations The camera sensitivity is normally give for the above case when the source is in one of the four chop nod beams However if the source is single and compact the chop and nod throws can be chosen 104 MIRAC User s Manual to place the source in different positions on the array in each of the four beams When the four beams are differenced the source is positive in two of the positions and negative in the other two In this case the sensitivity for a given observing time is greater by a factor of two A1 2 Integration Times and Chop Nod Options By integration time we mean the accumulated time in one beam from the coadded frames in an observation We refer to the on chip integration time as the frame time Since the array is read out at a frame rate of approximately 10 1000 hz there are many individual frames which are coadded in the electronics and digital signal processor board to produce a single observation at one location on the sky The standard technique used with MIRAC is to take a large number of chop nod sets with an integration time of 5 30 seconds in one beam 20 120 seconds total time chop nod This integration time is short enough to minimizes image degradation due to telescope drift or changes in the sky during the period of the integration and long enough to maintain a good observing duty cy
300. type out lines containing the string in more than one file grep v search string filename s to type out lines that don t contain the string 7 Timesavers 7 1 Aliases To alias or abbreviate a command string with an alias string type aliasalias string command string 8 History Command Repetition Repeat the entire last command line at any point in the current command line 1 Repeat the last word of the last command line at any point in the current command line 9 Run Command in Background Job Control To run a command in the background as opposed to the more common method of running commands in the foreground type a amp after the command line Then you can type more commands to the command prompt or even run more commands in the background for simultaneous command execution 10 Online Documentation To see online Man Pages type mancommand name Doing More with SunOS Quick Reference This quick reference lists commands presented in this manual including a syntax diagram and brief description T Files 11 Filename Substitution Wild Cards Character Class c Range c c c is any single character String Class strLstr str is a combination of characters wild cards embedded character classes and embedded string classes Home Directory Home Directory of Another User user List Hidden Files Is 1 a 12 File Properties Seeing Permissions ls 1 filename Changing Per
301. uld be used rfits 91 oldirafname yes datatype real This will read in all files and convert them to IRAF images with the file name 191 as real numbers The old FITS files can then be deleted and all processing done on the IRAF images 5 22 99 Glossary 101 Glossary of Terms Burst mode The array is read in a burst then there is a delay for a selected number of read times while the array integrates flux until the next read Chop Motion of the secondary that causes the telescope beam to look at two different positions on the sky This motion is performed synchronously with the data taking so that images of both sky positions are obtained A typical distance between chop beams is 20 arcsec and 10 msec wait to allow the chopper to settle on the new position Coimage a set of frames co added on the signal processor boards at the camera Column the vertical direction on the array there are 128 columns on the array The array is read out in blocks with 2 columns and 8 rows in each block and then rearranged in the DSP to form the image Flat field an image of the background 1 sky telescope emission This image can be subtracted from the on source observation to remove the background and leave only the source emission in the image Frame a single array readout typically taking 1 millisecond Gain map A map which contains the reciprocal of the relative gain of each pixel in the detector array normalized to
302. us entry for this source 5 22 99 6 Nightly Startup and Shutdown Check Lists 35 18 Set Next parameters THESE SHOULD BE CHECKED FOR EVERY SET OF OBSERVATIONS Object name Wavelength Integration time Frame time Typical values in Table 7 1 This can be automatically set for each filter when Link Frame Filter is on Section 7 3 Chop nod mode Continuous coimaging Obs Mode Save on off Read Offsets on off Use command file on off Link Frame Filter on off Note A number of MIRAC macros are useful for this 19 In the event that camera power is shut off and on again repeat the procedure in Items 12 and 20 21 6 2 1 2 3 4 13 to reinitialize the DSP and camera In the event that the MIRAC program hangs up and the computer is reboot Ctrl Alt Del execute MIRAC lt enter gt and repeat the procedure in Items 5 12 and 13 to load the DSP program and reinitialize the DSP and the camera The parameter values last saved in current hdr will be reloaded The next file number will not be up to date and should be corrected in Obs Save Other parameters must be checked It is also advisable to repeat Item 14 to reinitialize the filters In the event that the MIRAC computer power is shut off and on again reload and initialize the DSP and camera as given in Items 5 12 and 13 Nightly Shutdown Tasks Turn off facility secondary chopper control Turn off telescope status and video monito
303. ut fully including the zeros in the extension This first file sets the default file date to 3 17 95 so then all subsequent file references can be accessed using the shorthand notation To select one of the two images in a chop or four file names in a chop nod observation use a colon with the image number 1 4 e g 950317 005 2 9 4 Main Screen Display The main screen display is shown in Figure 9 1 This and other screen displays are obtained using Word Perfect Grab TSR program Alt Shft F9 with the settings color default VGA Force BW off arcsec grid yellow autorange 2 00 5 00 blip settings normal detector electron gain 1 91 5 22 99 9 Using MIRAC Program 61 electrons ADU 3191 and blank flux 0 gain matrix flat with value 0983 simulator normalization 1 0 and width 3 0 chop 10 9 Hz frame 19 7 msec and integration time 96 sec The display consists of nine areas top command line 2nd line run status bar next 5 lines observing parameters center graphic array image with compass directions at the upper right if on left graphic FWHM plot if on right graphic magnified image if on lower right graphic source radial profile if on next 9 lines image statistics if on and bottom 2 lines observing and display status The command line contains both immediate commands and pull down menus The observing parameters displays the current parameter settings whether the array display is a current or past
304. vX tar Z where the X is the version number of the latest release Copy this file to its own directory and execute the following commands uncompress mrc2ftsvX tar Z tar xvf mrc2ftsvX tar At this point you should edit the file Makefile if necessary to conform to your system The default configuration is for a Sun workstation running SunOS 4 3 Possible changes necessary include pointing to the location of the ANSI C compiler on your system A port to little endian machines such as the DEC vaxstation has been done by Joseph Harrington you must use the commented lines in the Makefile instead of the ones set up as default Once this has been completed issue the following command make and the executable file mrc2fts will be created To convert the data the program is executed with the data name as an argument For example to convert the file 920605 440 the following command is given mrc2fts c920605a 440 and the file 1920605 440 is produced There are several options that may also be used when converting files g gainfile use the file gainfile as a gain map The gainfile must be in FITS format The values in gainfile are multiplied with the data values before expanding and flipping the image e exfac expand the image by the factor exfac usually 4 132 MIRAC User s Manual m maskfile use the file maskfile as a bad pixel mask Good pixels in the mask file should be set to 1 bad pixels to zero The file must b
305. wavelength or per night of observing Other commands will be slightly different on your computer such as the command to change to the data directory 1 below or to copy the programs to the current directory 2 Also may want to run the various routines and programs with different parameters See the individual program documentation for details NOAO SUN IRAF Revision 2 10 1EXPORT Fri Jul 24 11 23 23 MST 1992 This is the EXPORT version of Sun IRAF V2 10 1 for SunOS 4 1 Welcome to IRAF list the available commands type or get detailed information about a command type help command To run a command or load a package type its name Typ bye to exit a package or logout to get out of the CL Type news to find out what is new in the version of the system you are using The following commands or packages are currently defined ctio images local pipeline softools utilities dataio language noao plot stsdas dbms lists obsolete proto system cl cd cscr s2 hora mrc decl0 ex cl cp mrcreduct 22 cl cl initreduct cl 2 3 cl mrc2fts 921210 r 219 298 n 4 Reading c921210a 219 writing 921210a 219 Reading c921210a 220 writing 921210a 220 Reading c921210a 298 writing 921210a 298 cl rfits f92 oldirafnamet 255 IRAF filename a File 0001 1 0 AIRMASS Size 32 x 20 File 0001 restored to IRAF File 1921210 219
306. ween two files differences comp diff Translates characters N A N A tr List files and directories dir dir Is Change working directory set default chdir cd cd Show working directory s name show default cd pwd Make a directory create dir mkdir md mkdir Remove a directory delete rmdir rd rmdir Show disk usage show quota chkdsk quota Show disk status show device disk vol df Tape archiving backup diskcopy tar Message system mail N A mail Write a message to another user send rvax only N A write Talk to another user phone N A talk File transfer program ftp telnet kermit kermit procomm ftp telnet kermit Display process status show system ver ps Create a new process spawn command csh sh Terminate a process stop id ctrl alt dlt kill Some available editors edt eve vi edlin vi ed ex emacs C compiler cc link microsoft cc FORTRAN compiler fortran microsoft 77 77 Debuggers dbx 228 MIRAC User s Manual A20 2 SunOS Quick Reference 1 Work Session 11 LogIn Type username to system login prompt Type password to password prompt 12 Change Password Type passwd followed by old password and repeat new password 13 Log Out Type logout or CTRL D depending upon system setup 2 File System 2 1 Create File Type cat filename then text ending with CTRL D or see Editing Files 2 2 Make or Create Directory Type mkdir directory name 2 3 Look at File Type cat filename or more
307. which a pixel equals for the standard settings for several telescopes For the f 36 and f 15 telescopes magnification less than and pixel and field size larger than the boldfaced values should not be used due to vignetting for these magnifications and f ratios Table 2 1 Magnification and Pixel Sizes Nominal settings are in bold face type Telescope Aperture Focal Ratio Scale Mag Pix Field A for m mm arcsec arcsec Pix 2D S O 90in 2 3 1 45 1 99 43 35 44 7 6 3 0 36 8 1 87 43 33 42 9 5 46 30 37 8 5 UKIRT 3 75 1 36 1 53 43 27 33 9 5 46 25 30 8 5 6 5 1 15 2 12 57 28 36 17 4 8 20 25 9 12 5 1 16 20 7 10 1 14 14 18 2 8 8 KeckII 10 f 40 522 43 091 11 5 9 1 5 23 99 2 Overview Performance 7 2 4 Filter Selections The filter selections and properties are given in Table 2 2 This table gives the effective wavelength half power points and filter mean transmission over the and each weighted by the detector photon response The overall throughput is the product of the window optics and filter transmissions and the detector photon response Typical filter change times are given in Table 7 2 Table 2 2 MIRAC Filters Filter Waveln Ai Bandwdth trans Overall um um um um fraction mission thruput 2 2 2 02 2 38 35 16 3 8 3 5 4 1 61 16 4 8 4 42 5 18 277 16 7 9 7 74 8 06 32 04 8 8 8 36 9 24 88 10 9 8 9 31 10 29 98 10 10 3 9 79 10 82 1 03 10 10 6 8 11 13 09 4 98 47 117 11 14 12 2
308. within the packed file is assigned its own observation number as is done with data taken in the normal mode so the packed data file numbers are incremented by the number of observations per run For example if the current observation number is 647 and the user is taking data in the fast data mode with 10 observations per Run command then the packed files will be named PyymmddA 647 PyymmddA 657 To display or process images taken in the fast data mode the packed files must first be unpacked where they are written to individual image files in the usual format This is done using the unpack utility UTIL Functi Unpack Fast Data Files described in Section 12 7 or by mrc2fts described in Appendix 7 The fast data mode can be used in the Grab or Chop mode with either nod off or 2 beam nod In the two beam nod mode the number of observations per Run parameter specifies how many Grab or Chop images to take in each beam So if the mode is set to Chop Nod and fast data on with 10 observations per run command then the program will take 10 fast data chop images in beam 1 then offset to beam 2 and take another 10 fast data chops 9 9 3 Ultra Fast Mode The ultrafast mode takes bursts of a 64x64 subarray and saves them to a packed file at rates up to 80 images per second displaying the last image The partial array size must be set in OBS Header Hardware A B C and D There are no gaps between the images except for chopper delays t
309. xels remaining below the Object Detection Sigma threshold when a fit is not enabled or outside the radius of the Source inclusion width factor times the FWHM of the fit function when a fit function is enabled In the former case the maximum number of iterations is given by the Limit for BKG iterations When a fit function is enabled but Calculate source model sum 1s disabled the source sum is given by the sum of the signal relative to the mean background within a the source inclusion with faction times the FWHM of the fit When a fit is not enabled the source strength is the sum of the values of the pixels above the object detection limit relative to the background When Calculate source model sum is enabled the source sum is calculating by integrating the fit function using the parameters FWHM peak and background level Weight data in fit when on causes larger data values to be more heavily weighted in the source fit When off all weights set to 1 Autorange settings permits setting the display range to the minimum and maximum in the image to a upper and lower limit in number of noise sigma from the mean or to manual values which are set in DISP Begin Gray Gray Region for stats permits selecting a portion of the display for source detection and noise calculation This is useful when a source is in more than one chop nod beam Invert new data converts any source in a negative chop nod beam to a positive source in the display Other entrie
310. y 12 Table 7 1 MIRAC3 IRTF Typical Frame Times msec 41 Table 7 2 Falter Change TIMES 2 EROR eO Sees 42 Table 7 3 BOCUS SERIES Care css 47 Table 7 4 Printer Timings 51 Table 2 1 Standard Stars with Magnitudes Ordered by Right Ascension 108 Table A2 2 Standard Stars with Magnitudes in Alphabetical Order 109 Table A2 3 Standard Stars with Flux Density in Alphabetical Order 110 Table A14 1 Cryostat Capacity and Hold Time 183 Table A14 2 Cryogen Consumption 183 Table A14 3 Temperature Controller 193 Table A14 4 Cryostat Pupil 194 Table A14 5 Cryostat Magnification 8 6 195 Table A17 1 Bias Inputs Detector Cold 213 Table A17 2 Bias Inputs Detector Room Temperature 215 Table A17 3 Bias Inputs Detector Input Continuity at Room Temperature 216 Table A17 4 Signal Outputs 12 c sehe SENE SETS 217 Table A17 5 Grounds and Array Temperature
311. y a factor of 1 26 and point source sensitivity greater by a factor of approximately 1 6 2 7 Telescope and Sky Emissivity The telescope and sky emissivity was determined at the Steward Observatory 2 3 m telescope on Kitt Peak December 9 1992 The cryostat window was ZnSe The ambient temperature 10 C The results are shown in Table 2 5 The camera beam spill over beyond the secondary was determined by comparing the background signal with and without a cardboard annulus around the secondary 12 Waveln um 8 8 9 8 11 7 12 5 20 6 Zenith Backgnd Digital Units 417 1430 783 1027 MIRAC User s Manual Table 2 5 Telescope and Sky Emissivity Total Emiss ivity 148 270 119 156 Window Emiss ivity 001 001 001 001 Di chroic Emiss ivity 027 027 027 027 Tele scope Sky Emiss Emiss ivity ivity 5 22 99 3 Observing Run Arrangements 13 3 Observing Run Arrangements 3 1 Observing Proposals Outside proposals for MIRAC3 on the MMT IRTF and UKIRT in collaboration with the MIRAC team are welcomed This collaboration includes both the observing proposal and subsequent reduction and publication of the data Collaborators should be prepared to contribute to the shipping and cryogen costs for the observing The liquid helium cost at the IRTF is approximately 100 per day The shipping cost from Tucson to Hawaii is 1600 to 2000 round trip The draft proposal should be circulated to the MIRA
312. y the gain and mask etc Z corrects a chopped observation for which chop wait was set to zero If the wait was not set to zero there is a warning message and no correction is made Example 1 convert 10 files 5 14 taken in GRAB mode on August 30 1993 mrc2fts 930830 r 5 14 Example 2 convert 30 files 37 66 taken on 8 30 93 normalizing by gain117 map and using mask8 93 msk expanding by a factor of 4 mrc2fts c930830a r 37 66 g gainll7 map m mask8 93 msk e 4 5 22 99 8 Atmospheric Extinction and the aircor Program 133 Appendix 8 Atmospheric Extinction and the aircor Program A8 1 Infrared Atmospheric Extinction The earth s atmosphere absorbs IR radiation from astronomical sources The absorption or atmospheric extinction is dependent on the airmass since that determines the path length and column density of the line of sight to the source The airmass is related to the angle from zenith by the approximation Airmass sec Z 1 cos Z where Z is the angle from zenith It is likely that the various sources and standard stars are observed at different airmasses throughout the night In order to properly calibrate the images the flux must be normalized to a common airmass usually 1 0 or at zenith This is done by determining the extinction value and then applying a multiplicative correction to the raw data based on the extinction and the airmass of the data Under photometric conditions the extinction value
313. yed to the screen in any way Main image display screen the screen that is displayed when the program is in one of the top line main menus such as OBS PRN DISP or UTIL If the display option of Array has been selected in DISP Options for Display then the data in the Image Display Buffer will be displayed in the center of the screen Nod or Wobble Offset that is performed where the telescope is offset to a new sky position to take an integration usually off source A typical nod vector is 30 arcsec and 3 4 seconds must be allowed for the motion to complete before beginning the next integration Observation the data set consisting of many images coadded frames from the camera including all separate chop and nod frames which are saved as a single file on the PC For example in the typical nod observations there will be two chop pairs at each nod position The source will be in the first image of the first chop pair and the other three images will be of blank sky Row the horizontal direction of the array there are 128 rows The array is read out in blocks of 2 columns by 8 rows and rearranged in the DSP to form the image Run an automated set of observations carried out in sequence as given by OBS Mode How many Obs Run 5 22 99 Al Principles of Mid IR Observing 103 Appendix 1 Principles of Mid IR Observing 1 1 Mid IR Observing with Chopping Nodding and Offsetting Observing at mid IR wavelengths from gr
314. ys after the end of the run The data stored by MIRAC should be accessed with an individual guest account It is best to establish just one guest account for a particular observing program To obtain a guest account login on herschel or wien as guests respond to password request with enter once or twice provide your name observing program number and a password start using the new account 5 22 99 5 Start and End of Run Setup and Shutdown Check Lists 21 5 Start and End of Run Setup and Shutdown Check Lists The convention for indicating MIRAC program commands in this and subsequent chapters is of the form OBS Header Observe Chop Frequency where each item separated by is executed by a single key stroke the first letter of the item The first item is the command line Subsequent items are menus or selections within a menu A parameter such as Chop Frequency above is entered with enter Page up moves one menu back up esc returns to the command line exits the menu canceling the changes that have been made It is also possible to move through the command line and menus with the cursor arrow keys 5 1 Preparation of MIRAC after Shipping or Storage If MIRAC has been shipped or in storage follow the unpacking and setup instructions in Appendices 13 and 14 5 2 Start of Run Setup Tasks Before carrying out these tasks the Software Preparation and Hardware Preparation and Setup Chapter 4 and Appendix 14 shou
315. zed by the program All others are regarded as Targets The new version of the CATALOG program by Dave Harvey 5 89 does not allow for the TYPE field to be filled by text so these must be stripped from the file if one wants to use that program The output is sent to the standard output usually the screen To send the output to a file so that it can be printed use the redirection symbol on the command line in DOS or UNIX Examples are given below A number of command line options are available Several predefined observatory sites may be selected with the o option The number of columns on a page may be determined with the c option The range of UT may be selected with the r option usage airmass sourcefile mm dd yyyy a t s c n oxx r n1 n2 where sourcefile file name of source list telescope format mm dd yyyy month day year of desired night Optional command line switches a specifies maximum airmass default 2 5 124 MIRAC User s Manual t specifies targets only s specifies standards only c number of columns in output default 7 oxx specifies observatory where xx is kp Kitt Peak default ml Mt Lemmon mk Mauna Kea ct Cerro Tololo specify range of UT where nl and n2 are the start and end UT 0 and 14 are the defaults p put page numbers at top right of page default none A few examples follow airmass sources cat 3 13 1993 s c 3 omk this prints to the screen the airmas

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