"user manual"
Contents
1. REQ FPR 0508 The engineering interface will be capable of commanding and controlling all MCAO mechanisms doing all necessary and low level operations with the real time computer reading data from the various sensors and detectors reading status from all sensors 5 6 3 4 Data capture REQ FPR 0509 The engineering interface will be capable of capturing the data from the MCAO system 5 7 Other requirements 5 7 1 Documentation REQ FPR 0601 The MCAO system will be delivered with adequate documentation to facilitate its operation maintenance and repair 5 7 1 1 User s Manual REQ FPR 0602 The user s manual shall be written to enable a new user to get easily acquainted with its operation 5 7 1 2 Service and calibration manuals REQ FPR 0603 A manual will be written to enable Gemini technical support personnel to maintain the MCAO system This manual will include documentation to describe the calibration required to optimize the operation of the system at the specification level 5 7 1 3 Software maintenance manual REQ FPR 0604 A software maintenance manual will be provided to enable Gemini software maintenance staff to maintain the MCAO software 5 7 1 4 As built drawings REQ FPR 0605 The as built drawings will show all the dimensions in millimeters down to 0 01 mm All fasteners specified in these drawings will be standard metric sizes All drawings shall otherwise be to RSAA standards used in instruments of sim2. 4 ml M Na Abundance 10 cm JFMAMJJASOND Month 4 4 Environmental conditions The temperature in the dome will vary between 10 and 20 degrees Celsius Page 8 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 Complete System Requirements This section lists the top level science requirements the performance requirements and the functional requirements for the complete MCAO system The latter includes e The AO Module Module mounted to the ISS and including the AO compensation system as such It acts as an interface between the telescope and the instruments It contains the re imaging optics deformable mirrors LGS and NGS sensors By extension this also includes all the electronics and control systems e The laser system and laser control system This is the laser s itself and its control system e The beam transfer optics and laser launch telescope Optical relay from the laser system to the top of the secondary The LLT is the last part which expand the beam to a larger diameter and assures beam pointing This includes the BTO and LLT control systems e SALSA This is the safety system which primary function is to detect approaching aircraft Its only connection to the AO system is a broadcast signal which interrupt the laser propagation The requirements listed in this section apply either to the whole system or to each subsystem 5 1 Top Level Science Requirements
3. 5 1 1 Wavelength Coverage REQ FPR 0001 MCAO will pass the 1 2 5um wavelength range to the instrument It will be possible to also pass the 0 8 1 0 micron range with requirement of a changeable dichroic A goal is to extend observations to 5um and not preclude use to 0 5um 5 1 2 Throughput REQ FPR 0002 The deployment of AO will not lower the telescope throughput by more than an average of 25 over the baseline wavelength range At no wavelength it should be more than 30 With a changeable dichroic the same throughput specification is required for 0 85 1 0um 5 1 3 Emissivity REQ FPR 0003 The total emissivity of the telescope and AO system without atmospheric dispersion compensation in K must be lt 19 with a goal of this emissivity out to Sum 5 1 4 Flat Fielding REQ FPR 0004 It is required that the flat field instability does not cause systematic effects larger than the photon noise over a 5x5 arcsec region within a one hour integration in J through K narrow and wide bandpasses It is a goal to match this in L and M 5 1 5 Strehl Ratio REQ FPR 0005 The MCAO system will deliver a minimum AO only average H band Strehl ratio of 0 54 over the central one arcmin square of the compensated field of view This specification will be reached for any period of time of 15 minutes during median seeing conditions at or about zenith at the output of the MCAO system excluding telescope and instrument aberrations but including
4. 5 1 16 Astrometric accuracy Field distortion sise 11 Sd bz Number of NGS A cic its i estet id based dab gous Pee tede dt ei det tases det te eet 11 SAAS GHOSTS ING BES i sion a n A A 11 5 119 Scattered Light level te eta e e aee eth e tales e teet 11 5 2 MECHANICAL REQUIREMENTS eee e 208 siren ase nn Sek Oa es EON EL Seabee A EUR SENE a a 11 5 2 1 SUN tte A A ie 11 2 212 Timeto JUAN A A ER E 11 5 2 3 Thermal toleranten s s d ea Le e di 11 5 244 Meiric AMENA ee eit a eg e hak Pass cete bad Seda et das te t es 11 5 2 5 Metric dimensions on drawings sise 11 3 2 6 MEC fasteners id e t eee e ate idee e ae te tie E e et D eee ete e eda 12 5 3 CONTROL SYSTEM REQUIREMENTS cccccceesveessecsctccnesssesscecstncovecssvcccetecsassesssecctecesscsssesceccuaessecsveccteecenessevces 12 5 3 1 Operability a d stent benedi iouis de A te its 12 3 3 2 Configuration tinte e e o een esee ten m id inu 12 3 3 3 Impactonanechanism aceurdey lla loan 12 5 3 4 Impact on scientific performan ersan n n n a a i nae 12 5 3 5 Temperature CMA oie cada 12 5 4 ELECTRICAL AND ELECTRONIC REQUIREMENTS ssssssecccceecesssececccceeeeaseeecccceeecuanseeeccceessuaaseeeeceesssauaneeeceees 12 5 4 1 Grounding and shielding ix eei pic uibs a alas leas alate 12 5 4 2 Electrostaticdischargen ciao da 13 Page 4 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 4 3 Power Consumption i ve
5. REQ FPR 0502 The MCAO system will use a standard Gemini configuration of a workstation for the operator interface to an EPICS based system used for controlling motors and for receiving status information from sensors 5 6 1 2 EPICS system REQ FPR 0503 The EPICS system will be a standard Gemini Unit VME crate MPC750 CPU VxWorks operating system 5 6 2 EPICS compatibility 5 6 2 1 Interfaces to the Gemini system REQ FPR 0504 Interfaces to the Gemini system will conform to the descriptions presented in the core ICS documentation Interfaces to other Gemini subsystems will conform to the relevant ICD 5 6 3 Engineering Interface REQ FPR 0505 The MCAO system will provide a means for command and control of the MCAO mechanisms detector controllers and real time computer without the need for having the Gemini control systems i e the OCS TCS etc present or connected 5 6 3 1 Physical interface REQ FPR 0506 The Engineering interface will use a Sun Solaris workstation of the same type as that used for the instrument control system that runs with other Gemini control systems Page 14 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 6 3 2 User Interface REQ FPR 0507 To the extent practicable the user interface in the engineering interface should appear to a user to be similar to the Gemini observing tool although it will be at much lower level 5 6 3 3 Command and control
6. Strehl at 1 65 microns Atmospheric Compensation Fitting Error Anisoplanatism LGS Noise and Servo Lag NGS Noise and Servo Lag Bright Stars Scintillation equivalent OPD Wind Shake TBR Implementation Errors Uncorrectable and Non Common Path Errors System Calibration Errors TBR LGS Calibration Errors TBR Total RMS OPD Strehl Ratio at 0 85 microns Strehl Ratio at 1 25 microns Strehl Ratio at 1 65 microns Strehl Ratio at 2 20 microns Page 24 of 24 07 11 01
7. amount of heat that can be carried away from the Laser System is 5 kW 7 2 3 Laser System Control System REQ FPR 0811 The Laser System has its own Control System CS made of hardware and related software The LS CS must be able to control the LS remotely All LS controls commands and signals must be accessible from the CP control room 7 2 3 1 LS CS functionalities REQ FPR 0812 The LS CS must interface with the MCAO Control System and provide the following elementary tasks and sequences REQ FPR 081 2a Prior to start internal check REQ FPR 0812b Automated start up REQ FPR 0812c Automated shutdown REQ FPR 0812d Emergency shutdown REQ FPR 0813 If pulsed at a repetition rate close to 800 Hz the LS shot to shot pulses must be controllable from an external signal 1 2 3 2 LS diagnostics REQ FPR 0814 The LS has suitable diagnostics to produce and maintain the sodium light The following parameters are monitored in real time from the control room output power near field and far field spatial profiles temporal profile if the laser is pulsed spectral profile Page 21 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI REQ FPR 0815 The following parameters are monitored as well LS internal status temperature in the laser enclosure coolant temperature and flow rate accumulated hours REQ FPR 0816 All status information and relevant diagnostics parameters are logged for maintenance
8. field See REQ FPR 0016 for time variable field distortions 6 1 1 8 Atmospheric dispersion compensation See REQ FPR 0013 6 1 1 9 Natural guide star path ADC REQ FPR 0708 Each NGS beam will be compensated for atmospheric dispersion down to a residual spectral dispersion of 0 05 FWHM 6 1 1 10 LGS path mirror and lens coatings REQ FPR 0709 Special optimized coating will be used in this path to optimize the transmission 6 1 1 11 LGS light in NGS path REQ FPR 0710 A notch filter of equivalent should be used to cut down the LGS stray light to lt 30 of the night sky background 6 1 1 12 Nitrogen flow over pressure To maximize the length of time over which the throughput and emissivity requirement is met it is advised that the interior of the AO module be kept under a slight overpressure using Nitrogen 6 1 2 Mechanical requirements 6 1 2 1 Flexures image motion REQ FPR 0711 The OIWFS will compensate for the image motion induced by flexures However these flexures should be kept in a reasonable range The image motion induced by flexure in the output F 30 focal plane should be smaller that 2 arcsec equivalent on the sky for a motion from zenith to 45 degrees zenith angle 6 1 2 2 Position accuracy of the NGS probe positioning system REQ FPR 0712 The NGS probes will be able to be positioned at better than 0 02 equivalent on the sky The additional offsets to meet requirement REQ FPR 0016 will be electr
9. includes the effect of the instrument This set of PSFs shall be saved in a coordinated manner with the science instrument data Page 10 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 1 15 Diagnostics REQ FPR 0015 There will be real time and logged information about ro To Lo and 8 These values shall be saved together with the instrument data Accuracy of 10 is required on ro 20 on To Lo and 66 5 1 16 Astrometric accuracy Field distortion REQ FPR 0016 The MCAO system shall not introduce static or quasi static plate scale changes of more than 30 parts in a million e g 3 milliarcsec over 100 arcsec in addition to the fixed field distortion induced by the optics that can be calibrated 5 1 17 Number of NGS REQ FPR 0017 Although the above specifications of the MCAO system are stated when using 3 natural guide stars to correct the low order modes it is a requirement that the system may work with reduced performance with two or one natural guide stars 5 1 18 Ghosts images REQ FPR 0018 Ghost images generated in the MCAO optics must be at a level below 10 from the parent image They should be characterized and predictable 5 1 19 Scattered light level REQ FPR 0019 The total amount of light scattered by the MCAO optics should be 2 goal 1 of the light entering the AOM 5 2 Mechanical requirements 5 2 1 Safety REQ FPR 0101 No mechanisms will move in the even
10. instrument from the ISS and while mounted with other instruments 6 1 4 Mass and center of gravity requirements 6 1 4 1 Total mass REQ FPR 0721 The AOM including its support frame thermal enclosures electronics and all cabling and services connections will have a mass of 2000 kg 6 1 4 2 Center of gravity REQ FPR 0722 The AOM including its support frame thermal enclosures electronics and all cabling and services connections will have a center of gravity on the port axis 1000mm from the mechanical interface on the ISS 6 1 4 3 Balance tolerance REQ FPR 0723 In any orientation of the telescope and rotator the imbalance caused by the AOM must not exceed 400Nm with respect to the telescope elevation axis This will include static imbalance and any change in mass moment due to moving elements 6 1 4 4 Ballast weight REQ FPR 0724 A ballast weight and its supporting structure will be supplied as required to meet the above requirements 6 1 45 Instrument handling REQ FPR 0725 The AO module support frame will have feet allowing the instrument to be stored free standing and attachment points for the Gemini instrument handling facilities Page 19 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 6 1 5 Electrical and electronic requirements 6 15 1 Power dissipation REQ FPR 0726 The AOM will be designed so that the total heat released to the Gemini dome air does not exceed 50
11. needed See REQ FPR 0015 7 Laser System and Laser Control System 7 1 Performance Requirements Table 4 Performance and Performance Stability of Laser System Quantity Requirement hour dev at 24 hour measured at output of LLT mht devinin Power Watts REQ FPR 0801 5x7 2W eq CW lt 1W per beam lt 1W per beam Beam Quality xDL REQ FPR 0802 lt 1 5 lt 0 1 lt 0 1 Wavelength REQ FPR 0803 589 nm peak of lt 100MHZ lt 100MHZ sodium D2 line Page 20 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI sodium D2 line Polarization REQ FPR 0804 circular lt 10 lt 10 7 2 Functional Requirements 7 2 1 Laser System location REQ FPR 0805 The Laser System or the last stage of the LS is mounted on the telescope center section This is a goal and not a requirement 1 2 2 Electrical and electronic requirements 7 2 2 1 Power Dissipation REQ FPR 0806 The LS will be designed so that the total heat released to the Gemini dome air does not exceed 50W REQ FPR 0807 The heat conducted into the telescope structure will not exceed 50W REQ FPR 0808 Individual elements exposed to the air volume will not attain a temperature of 2 degrees C above ambient 1 2 3 3 Power consumption REQ FPR 0809 The LS power consumption will be lower than 190 kW 3 phases 208 VAC 30 Amps max 7 2 2 3 Cooling REQ FPR 0810 The maximum
12. 10W REQ FPR 0916 The BTO will be designed so that the total heat released between the laser system and the secondary mirror does not exceed 10W excluding the beam dump REQ FPR 0917 The beam dump will be designed so that the total heat released does not exceed 10W 8 2 4 Maintenance requirements REQ FPR 0918 Whenever possible the BTO and LLT optics are protected from dust by covers 8 2 5 Light scattering REQ FPR 0919 The BTO and LLT designs minimize laser light scattered in the dome 9 SALSA 9 1 Performance Requirements REQ FPR 1001 The aircraft monitoring systems must be able to detect commercial military and private aircraft REQ FPR 1002 The detection to beam crossing time must be greater than 1 second The goal for the time between detection and beam crossing is several minutes 9 2 Functional requirements The system must meet the general system requirements for lifetime REQ FPR 0620 and maintenance REQ FPR 0611 In addition it must meet the following requirements REQ FPR 1003 All safety systems must be fully automated and require no user interaction to detect and shutter the laser beam The system will automatically be activated whenever the laser shutter is open and the telescope is pointing out an open enclosure shutter The system will also have a means to manually activate the systems REQ FPR 1004 The system startup time will be commensurate with the MCAO night time setup requirement REQ FPR 020
13. 2b Its startup procedure will include a means to verify that the system is working REQ FPR 1005 The systems will graphically and audibly notify the user of any pending beam crossings and report the estimated time to shutter closure Detected objects and their trajectories will be graphically displayed in the control room Page 23 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements 10 MCAO Strehl Ratio Budget The following table is patterned after the format found in the MK LGS OCDD Although all wave front errors are added in quadrature the phase variances associated with atmospheric turbulence compensation under section 3 0 have been reverse engineered to sum to values obtained by more detailed modeling This budget should be considered preliminary Quantities denoted TBR to be reviewed have been lifted direction from the MK LGS OCDD and require further analysis for the Gemini South MCAO system The remaining AO contributions in section 3 0 are based upon mean performance over a square 1 arc minute field MCAO Field Averaged Error Budget Bright NGS Zenith 30 degrees 45degrees 1 0 Telescope Limitations Strehl at 1 65 microns Primary Mirror Secondary Mirror Alignment Self Induced Seeing AO Fold Mirror Science Fold Mirror 2 0 Instrument Limitations Strehl at 1 65 microns Flexure relative to OIWFS Wavefront Quality 80 Zernike modes removed Wavefront quality TT and defocus removed 3 0 MCAO System
14. Gemini 8 m Telescope 670 N A Ohoku Place HILO HI 96720 GEMINI M CAO Functional and Performance Requirements Document Prepared By Francois Rigaut Contributors Mark Chun Brent Ellerbroek C line d Orgeville and Francois Rigaut Created February 14 2000 Last Modified May 13 2000 Date Approved By Group Manager Group Manager if req Systems Engineer M C AO MCAO Functional and Performance Requirements Page 2 of 24 07 11 01 VN MCAO GEMINI MCAO Functional and Performance Requirements Revision Control Revision No Author amp Date Approval amp Date Description Revision 1 F Rigaut May 1 2000 Original Document Page 3 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements MCAO FUNCTIONAL AND PERFORMANCE REQUIREMENTS DOCUMENT scsscssssssssscssscsccssssccsccsecsssssessecsesssesssssscceesses 1 1 PURPOSE OF THIS DOCUMENT cssscssscssscccsscssssecsssscsssecssssessscescnsscnssscsssscnssssscsssosessecsssssonsssossees 6 2 APPLICABLE DOCUMENT ssccssssssssscsssecsssecsssesscssessssscsssscssssssnsssonssscnssscsssssscssscnssssesescnsssssosssssessones 6 3 ACRONYMS A NN 7 4 OPERATIONAL CONDITIONS csscssssscsssscsssecsssscssssessssscsssecssssssssesesssscsssscsssssssssssnesscsssssssssssossssoessones 7 4 1 ATMOSPHERIC CONDITIONS roses sms bee Eee re Lee fentes s
15. W REQ FPR 0727 The heat conducted into the ISS structure will not exceed 50W REQ FPR 0728 Individual elements exposed to the air volume will not attain a temperature 2 degrees C above ambient 6 1 5 2 Cassegrain cable wrap interface REQ FPR 0729 All the connections from the AO module to the rest of the building will be through the cassegrain cable wrap 6 2 Software Requirements 6 2 1 Data processing and data storage 6 2 1 1 Circular buffers REQ FPR 0730 The AOM CS will be capable of storing up to 30 seconds of consecutive data including wavefront measurements deformable mirror commands mirror modes and real time loop status 6 2 1 2 PSF estimation REQ FPR 0731 The AOM CS will compute synchronized by an outside signal the necessary statistics to allow semi real time PSF reconstruction This will take into account wavefront measurements deformable mirror commands over the period of integration of the scientific instrument i e 30 seconds to several minutes See REQ FPR 0014 6 2 1 3 Real time atmospheric parameter estimation REQ FPR 0732 The AOM CS will provide real time estimation of ro to Lo 89 and the Cn2 profile These values shall be saved together with the instrument data Accuracy of 10 is required on ro 20 on To Lo and 64 Best effort on the Cn2 profile These estimations will be available while the loop is closed and when it is open This Cn2 profile will be used to optimize the AO reconstructor if
16. and debugging purposes All information is time stamped 8 Laser Launch Telescope and Beam Transfer Optics 8 1 Performance Requirements 8 1 1 Blind Pointing accuracy 8 1 1 1 Overall pointing accuracy REQ FPR 0901 Overall Pointing accuracy will be better than 1 arc second 8 1 1 2 Beam to beam offsets 8 1 2 J ittering REQ FPR 0902 Max Jittering of each beam at 800 Hz 0 05 REQ FPR 0903 Max jittering of each beam at 100 Hz 0 07 8 1 3 BTO LLT Optical quality REQ FPR 0904 The overall optical quality of the BTO LLT should not degrade significantly the laser beam quality as it is at the output of the LS The overall beam quality at the output of the launch telescope should be 1 5X diffraction limited REQ FPR 0905 It is a requirement that the LLT and BTO transmit as much laser power as possible to the sky The LLT transmission coefficient should be gt 95 and the BTO transmission coefficient should be gt 80 for a Laser System mounted on the telescope center section gt 60 for a Laser System mounted further down in the pier 8 2 Functional requirements The BTO and LLT will be designed to have the following functionalities REQ FPR 0906 Project an X shaped constellation of LGS on the sky with 1 LGS at the center and 4 LGS at each corners REQ FPR 0906a The angular distance from the central LGS to each LGS at the corner is 42 5 arcsec REQ FPR 0906b The LGS constellation is steady on the sky which impl
17. compensation of the wind shake and the MCAO system calibration errors This assumes the use of bright natural guide stars for the compensation of the low order terms The system is expected to deliver a commensurate performance at any wavelength of operation 0 34 at J 0 71 at K Page 9 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 1 6 Seeing limit for operation REQ FPR 0006 The system will be able to work under a variety of turbulence conditions In particular it should give commensurate performance to the one specified above for seeing values up to 1 2 arcsec 5 1 7 Transferred Field of view REQ FPR 0007 The MCAO system will transfer a circular unvignetted field of view of 2 arcmin in diameter to the instruments 5 1 8 PSF uniformity and field of view REQ FPR 0008 The Strehl ratio uniformity will be better than 4 rms in H band in the central one square arcmin over which the Strehl ratio specification REQ FPR 0005 is given In addition to the Strehl uniformity over the central one arcmin square the Strehl should be maximized everywhere in the field 5 1 9 Sky Coverage REQ FPR 0009 The sky coverage will be maximized for the specified Strehl ratios A minimum value of 10 at the galactic pole should be reached with a Strehl degradation of no more than 50 of the value specified in REQ FPR 0005 in H band LGS should be used and sensing of the tip tilt and low order modes on the NGS sh
18. d levee E RN 13 5 5 ENVIRONMENTAL REQUIREMENTS ccccceccseesossosesscacecseessceccnecteccseseesescescneedseceseeccssesevsessecesceeosevesdenccveesssese 13 29 Altitude requirements iiie aed ere ed ede pere o HE vod oe Re UR Ere Vokes PS E aaa 13 5 5 2 Temperature nvironment Em 13 5 5 3 Humidity environment i 3 ied aee ed aee e ten tel e e dde te ep bevels 14 5 5 4 Mechanical envtFonmehb i i ele ele eden ela eed 14 5 6 SOFTWARE REQUIREMENTS totes 14 5 6 1 Software design requirements sise 14 5 6 2 EPICS compatibility lt del 14 5 6 3 Engineering Interface lalola de 14 5 7 OTHER REQUIREMENTS cccccccssssssesccceccuecenseecccccsceeenseseccccsseennsesescecesaeanseeececessceanseececesseeenneesscecsueeensesesees 15 5 7 1 Documentation i oes Lee ep iste D ib M De sid detenti 15 5 7 2 Reliability te e es e lo EH IT 15 5 7 3 Maintainability and serviceability eese eene eene nennen ano nn non nn enne nnne 16 5 7 4 Lifetime and reliability aa cala 16 5 7 5 Safety ca stie tee Eee ii daa dica des 17 6 ADAPTIVE OPTICS MODPULLE aene eere ano eo Fe Geo eee ane age Cao eee p aee Cage e ao eer ina agebant ro eoa Cogo e aan root ioa eoa n s 17 6 1 PERFORMANCE REQUIREMENTS 5 eoe at ea au ea aue idad tante sd 17 6 1 1 Optical requirements ied edet etas ete estt tentent eme lea uated dle os bes tases ut odes Presiona 17 6 L2 Mechanical requirements ii e etes tddi 18 6 1 3 Space Requireme
19. ea DOVER e ERR dons Eo EEE E p SEKEREK EOE S ESEME e aenst 7 4 2 WIND SHAKE cies xo ER ee teet aiii ere E o eo des 7 4 3 SODIUM LAYER CONTENT iaa ev i e ete tete peu eie ne aet ot tege eet ved 8 44 ENVIRONMENTAL CONDITIONS eiie eese ette ih ove sate Ue cares 2083 cub PU Fee ln Nt sun s Eee eet eee mt Ne ere a e evo eo 8 5 COMPLETE SYSTEM REQUIREMENTS cesses ee eene eene nete nne tna setas etse tense tensa etas sets sets set ens sete sena 9 5 1 TOP LEVEL SCIENCE REQUIREMENTS ssssssccccecseceeseessncceeceaseeseeccceeessuesaueseeeecssaeeeeccesesssaanseeeeceeeeeeueneeeeees 9 5 1 1 Wavelength Cover ge ii Ac 9 5 1 2 Th EAU As a 9 5 1 3 EMUSSIVID s eee OO EE A Hu ti e E NE segs use ee NEU AAA AA E Sa 9 5 1 4 Flat Fielding I ugue n weed queen gend aue a 9 5 1 5 Sireh Ratio ahead ies 9 5 1 6 Seeing limit for operation dito fedt i d o ed ee e e ed landes feed 10 5 1 7 Transferred Field Of View i dad ed e d e e d d e repo 10 5 1 8 PSF uniformity and field of view etc eee itte a ineat 10 5 1 9 Sky CoVEFg8 idi n a A e e ep e d oe gu td eee e e eed i bed 10 S10 Ability to Dither ioi edle ee d aded ed a ftd daos 10 Sob LENA ld AAA RU UC TE Ee M UR had idee ORE MES 10 SD E25 2 E 30 output i ie e e A died f ed ftd das 10 5 1 13 Atmospheric Dispersion Compensator eee 10 DATA PSF CSUMGUON o edit e ue e RR E EGRE RR EC REESE tte 10 Didi dD DIGSHOSTIOS stie di A Pd AAA E ECC TQUE RE RENI e a 11
20. erhead specifications REQ FPR 0202a Day time prep operations hour REQ FPR 0202b Night time overall set up 10 min REQ FPR 0202c Object set up excludes telescope slewing and acquisition of 2 min TCS guide stars but includes TT probe arm positioning for minimum astrometric requirements REQ FPR 0202d Dithering 3s 5 3 3 Impact on mechanism accuracy REQ FPR 0203 The control system for MCAO will be designed so that the accuracy of the controllable mechanisms is not limited by the performance of the control system 5 3 4 Impact on scientific performance REQ FPR 0204 The control system will not impact on the scientific performance of the MCAO system 5 3 5 Temperature control DM temperatures monitored as needed for DM calibration Laser system temperature controlled as needed for wavelength stability and beam quality 5 4 Electrical and electronic requirements REQ FPR 0301 The MCAO system has to be designed in accordance with modern electronics engineering practice for astronomical applications 5 4 1 Grounding and shielding REQ FPR 0302 Separate ground returns shall be provided for low level signals noisy components such as relays and motors and hardware components such as mechanical enclosures chassis and racks Page 12 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 4 2 Electrostatic discharge REQ FPR 0303 The MCAO design will protect sens
21. han 9596 at 1 6 microns over the entire 2 arcmin field and at any point in this field The performance should be commensurate at any wavelength from 1 to 2 5 microns 91 at 1 25 microns and 97 at 2 2 microns REQ FPR 0702 The output focal plan should be flat within the above specifications REQ FPR 0703 Strehl variations within these specifications are acceptable if they are fixed and can be calibrated Optical requirements 6 1 1 2 Static PSF calibration REQ FPR 0704 The AO Module will provide artificial sources at the input focal plane to calibrate the static and or dynamic AO module instrument fixed optical aberrations REQ FPR 0705 This or these artificial sources will be diffraction limited at any wavelengths above one microns i e FWHM 5 mas 6 1 1 3 F 30 output See REQ FPR 0012 Page 17 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 6 1 1 4 Pupil location REQ FPR 0706 The pupil image location should be preserved by the AOM The intent is that the instrument background should not be increased by 0 5 TBC by this effect 6 1 1 5 Throughput See REQ FPR 0002 This requirement should be met over extended period of time 6 1 1 6 Emissivity See REQ FPR 0003 This requirement should be met over extended period of time 6 1 1 7 Field Distortion REQ FPR 0707 The fixed field distortion induced by the optical relay will not be greater than 2 TBC anywhere in the
22. hout damage 5 5 2 3 Transport temperature REQ FPR 0406 The MCAO system will be capable of withstanding a temperature range of 20 to 50 C during transport without damage Page 13 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 5 3 Humidity environment 5 5 3 1 Operation REQ FPR 0407 The MCAO system will be capable of being operated at altitude from sea level to the summit of Mauna Kea in the range of 0 to 90 relative humidity without damage 5 5 3 2 Transportation REQ FPR 0408 The MCAO system will be capable of being transported and stored in a wide range of altitude and temperature environments in the range of 0 to 100 relative humidity with condensing moisture 5 5 4 Mechanical environment 5 5 4 1 Telescope slew rate REQ FPR 0409 The MCAO system will be capable of withstanding slew rates of 2 degrees per second in azimuth and 0 75 degree per second in elevation or any combination of these along with rotation of the Cassegrain rotator to maintain alignment with the parallactic angle as it changes at these slew rates All optics and mechanisms will meet their specifications at these rates 5 6 Software requirements 5 6 1 Software design requirements REQ FPR 0501 The MCAO will be a conforming instrument in that it will use EPICS and conform to the Gemini software and control system standards and the requirements listed below 5 6 1 1 Use of EPICS
23. ies that the LLT BTO subsystems includes a de rotator REQ FPR 0907 Minimize requirement and adjust goal the 5 LGS spot sizes on the sky REQ FPR 0908 Maintain beam pointing and centering at all times requirement REQ FPR 0909 Maintain the laser circular polarization REQ FPR 0910 All LLT and BTO mobile elements must be remotely controlled by the MCAO Control System 8 2 1 LLT requirements REQ FPR 0911 The LLT is mounted on axis behind the telescope secondary mirror It must fit within the Secondary Support Structure SSS and must not disturb the Secondary Tip Tilt System M2TS functioning Page 22 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI REQ FPR 0912 It is an uncompromising requirement that the LLT does not obstruct the CP telescope secondary hole when MCAO is not in use The LLT design must be deployable 8 2 2 BTO requirements REQ FPR 0913 The BTO compensates for telescope flexures and thermal expansions which may disturb the beam alignment This does not introduce any vignetting REQ FPR 0914 The BTO includes two shutters one after the Laser System and the other one before the LLT The laser shutter located at the output of the LS is controlled by SALSA via the MCAO CS 8 2 3 Electrical and electronic requirements 82 3 1 Power dissipation REQ FPR 0915 The BTO and LLT will be designed so that the total heat released behind the secondary mirror does not exceed
24. ilar size function and complexity 5 1 1 5 Drawing standards REQ FPR 0606 All drawings will comply with US standard or a Gemini approved standard 5 7 2 Reliability REQ FPR 0607 The MCAO system will be designed and build to be reliable 5 7 2 1 Downtime REQ FPR 0608 The MCAO system will have a downtime of lt 10 schedule time on the telescope and where possible component failure will result in gradual performance degradation Page 15 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 1 2 2 Spares REQ FPR 0609 Single point failure that may result in significant downtime will be determined and where necessary critical spares will be identified 5 7 2 3 Continuous duty REQ FPR 0610 The MCAO system will be designed and built for continuous operation Modules containing moving parts e g Natural guide stars probes Laser guide stars focusing mechanisms ADCs will be designed or selected to meet requirements on downtime assuming continuous operation 5 7 3 Maintainability and serviceability REQ FPR 0611 The MCAO system shall meet the Gemini requirements for maintainability 5 7 3 1 Standard components REQ FPR 0612 Wherever possible the MCAO will use unmodified commercially available standard components 5 1 3 2 Modularity REQ FPR 0613 To the extent possible the MCAO will be designed to be modular 5 7 3 3 Access REQ FPR 0614 Access to the components and subas
25. itive components from electrostatic discharge 5 4 3 Power Consumption REQ FPR 0304 The total power used by the MCAO system should not be more than TBD W This splits into the various subsystems as follow Table 2 Subsystems power consumption specifications REQ FPR 0304a AOM TBD W REQ FPR 0304b LS LCS 190kW 3 phase 208 VAC 30 Amps max REQ FPR 0304c BTO LLT TBD W REQ FPR 0304d SALSA TBD W 5 5 Environmental requirements 5 5 1 Altitude requirements 5 5 1 1 Operation altitudes REQ FPR 0401 The MCAO system will be capable of being operated at any altitude between sea level and the Mauna Kea summit altitude 5 5 1 2 Storage altitude REQ FPR 0402 The MCAO system will be capable of being stored in or out of its shipping container at any altitude between sea level and the Mauna Kea summit altitude 5 5 1 3 Transportation altitude REQ FPR 0403 The MCAO system will be capable of being transported at any altitude between sea level and the altitude of the Mauna Kea summit by any transportation mode It will be capable of being transported by commercial jet with pressurized cargo compartments at altitude up to 15 km 5 5 2 Temperature environment 5 5 2 1 Operational temperature REQ FPR 0404 The MCAO operational environment will be limited to 15 to 25 C 5 5 2 2 Survival Temperature REQ FPR 0405 The MCAO system will be capable of surviving a temperature range of 20 to 50 C wit
26. nd better the functionalities of the system what it will do and how well and how fast it will do it The design is derived from this document This document takes precedence over other design and fabrication documents The design must serve the requirements in this document completely Every feature of the MCAO should be traceable to a requirement in this document and there should be no features of MCAO that are not required by this document The MCAO will be designed in stages with a review after each stage is complete Comments from the review committee will be folded into the design so the requirements will change as the design changes Therefore this document will be upgraded as needed after each major design review to maintain the correspondence between design and requirements This FPRD is largely inspired from the FPRD of Altair and NIFS 2 Applicable Documents Document ID Source Title SPE S G0041 Gemini Gemini System Error Budget Plan RPT AO G0091 Gemini Feasibility Study for A Multi Conjugate Adaptive Optics system for Gemini South Gemini MCAO OCDD Page 6 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements 3 Acronyms AOM Adaptive Optics Module BTO Beam Transfer Optics GS Guide Star ICD Interface Control Document ICS Instrument Controller Software package LCS Laser Control System LGS Laser Guide Star LLT Laser Launch Telescope LS Laser System LS CS Laser Sys
27. nis itae AAA ut dan e dot eo c ade d ede e idee 19 6 1 4 Mass and center of gravity requirements eee esee eene enne nnne nnne enne enne nnne enne 19 6 1 5 Electrical and electronic requirements ss 20 6 2 SOFTWARE REQUIREMENTS iive ete eL e RE e EUR oed EP o LE OU Ee qo get esu e e ee Te Rege 20 6 2 1 Data processing and data storage siennes 20 7 LASER SYSTEM AND LASER CONTROL SYSTEM 44e e eee eee e eee eene nenne ettet tense eese sette tease eese ee eeaa 20 7 1 PERFORMANCE REQUIREMENTS eeeeeeeeeeeeeeeene nnne eee rider SS SES Veer ESS S SS ris 20 7 2 F NCT NAT REQUIREMENTS 5 eh e M ne aM e eei a Mon E ST 21 7 2 1 Laser System LOCA On iue ue ed egere t ei o e E ege teo pe eMe 21 7 2 2 Electrical and electronic requirements ss 21 7 2 3 Laser System Control System sise rte eaa EUR E oe el ate ede pe ttu Ue E Ee Siea 21 8 LASER LAUNCH TELESCOPE AND BEAM TRANSFER OPTICS eere esee eee ee eee eene eene eee eas 22 8 1 PERFORMANCE REQUIREMENTS sssssccccceccesssseecccceeeessessecccceeesaueseeeccceessauasseeccceessauanseccccesssuansseeecesessuaanees 22 6 1 1 Blind Pointing aCCuracy A dE 22 8 1 2 Nal emer RES E REPRISE INIRE IA eer cee eee cee 22 6 1 3 BIOA LLT Op calquality uide size Steines HER MEOS ERR D E E EES Ea EEN SESS 22 8 2 FUNCTIONAL REQUIREMENTS csssssseccccccccessssecccceceeuuessecccceeeeaueseeecccesesauesseeccceeseauaneeccccesssaueesececese
28. onic offsets in the NGS control loop 6 1 2 3 Position repeatability of the NGS probes REQ FPR 0713 The NGS probes will be able to position themselves at a known previously used position with an error 0 01 Page 18 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 6 1 2 4 Flexures Strehl REQ FPR 0714 The Strehl ratio budget must be met at zenith angle from 0 to 60 degrees REQ FPR 0005 The flexure induced Strehl ratio loss should be smaller than 2 at H band and commensurate at the other wavelengths 6 1 3 Space Requirements REQ FPR 0715 The AOM will be designed to fulfill the space requirements for an instrument attached to the ISS 6 1 3 1 Electronics enclosure REQ FPR 0716 All AOM electronics enclosures mounted on the ISS will be counted in the space requirements as above Exception is the deformable mirrors HV power supplies TBD 6 1 3 2 Access to electronic enclosures REQ FPR 0717 The electronic enclosures will be accessible without removing the AOM from the ISS 6 1 3 3 Access to cooling water ports REQ FPR 0718 Cooling water ports on the AOM will be accessible without removing the instrument from the ISS 6 1 3 4 Access to dry air ports REQ FPR 0719 Dry air ports on the AOM will be accessible without removing the instrument from the ISS 6 1 3 5 Mechanical connections REQ FPR 0720 All mechanical connection on the AOM will be accessible without removing the
29. ould be optimized This specification applies when using the primary mode of observation all the visible light up to 0 95 micron is used for the TT sensing 5 1 10 Ability to Dither REQ FPR 0010 It must be possible to execute a dithering sequence with the AO system and a scientific instrument moving the science field on the science detector by several arcseconds 5 1 11 Zenith Angle REQ FPR 0011 The Strehl ratio specifications for the system are set at Zenith The system will be routinely operated at Zenith angles up to 60 degrees and in this range the system performance should be commensurate to the performance specified at Zenith 5 1 12 F 30 output REQ FPR 0012 The output F ratio of the AO module will be F 30 The telescope focal plane and pupil distance will be preserved 5 1 13 Atmospheric Dispersion Compensator REQ FPR 0013 The MCAO system will have its own science path atmospheric dispersion compensator covering the 0 80 2 5 microns domain over the 2 arcmin diameter field of view The residual atmospheric dispersion in any of the wide Near IR band will not reduce the Strehl ratio by more than 2 5 1 14 PSF estimation REQ FPR 0014 The system should have a PSF estimator PSF in function of the field position that delivers a PSF with 2 accuracy on the Strehl value This PSF estimator should include the effects of the atmosphere telescope MCAO system and ADC It is strongly desirable that this PSF estimator also
30. r an operational lifetime of 10 years without a major overhaul Components likely to affect the lifetime requirement will be identified Page 16 of 24 07 11 01 MCAO GEMINI MCAO Functional and Performance Requirements As per the Gemini Reliability and Maintainability Plan v 1 June 10 1994 every work package delivered to Gemini will include a preventive maintenance program This will include specification of the off line and scheduled maintenance as well as a suggested spare parts list Table 3 System Reliability Specifications Component Mean Time Between Mean Time to Repair Failures Complete System REQ FPR 0621a gt 80 24h AO module REQ FPR 0621b gt 1600 12h LS LCS minor fail REQ FPR 0621c gt 100 12h LS LCS major fail REQ FPR 0621d gt 900 1 week BTO LLT REQ FPR 0621e 2400 24h SALSA REQ FPR 0621f gt 3200 48h REQ FPR 0622 The LGS facility will be available for use no less than 1800 night time hours per year This is every other night or six months of night time use per year 5 1 5 Safety REQ FPR 0623 Normal considerations including compliance with applicable regulations will apply in the area of mechanical electrical electrostatic and laser safety 6 Adaptive Optics Module 6 1 Performance Requirements 6 1 1 6 1 1 1 Optical Quality REQ FPR 0701 The Strehl ratio of a static image at the output focal plan of the AOM should be better t
31. semblies will be considered in the MCAO design particularly for those elements that are accessed frequently Tool and hand clearances will be considered as well as space required to move the modules visual access to components or a means to feel their correct position and alignment 5 7 3 4 Alignment REQ FPR 0615 Alignment of optical components will be achieved to the extent possible by accurate machining of locating fixtures 5 7 3 5 Relative equipment arrangements REQ FPR 0616 Equipment will be located with due consideration of the sequence of operations involved in maintenance procedures To the extent possible the most accessible locations will be reserved for the items requiring most frequent access 5 7 3 6 Subassemblies REQ FPR 0617 Subassemblies of the equipment that require more frequent service inspection adjustment repair or replacement will be configured as plug in modules or if in racks as drawers that can be withdrawn easily 5 7 3 7 Handling REQ FPR 0618 Modules greater than 20 kg in mass will have suitable handles for use in removing replacing and carrying them Handles will be located such that the vector sum of resultant handling forces will pass close to the center of gravity of the unit 5 7 3 8 Revisability REQ FPR 0619 Multilayer electronics board will not be used unless they are replaceable as a module 5 7 4 Lifetime and reliability REQ FPR 0620 The MCAO system will be designed fo
32. ssuaannes 22 6 2 1 LET requirements e A radiaci n 22 8 2 2 BTO FEQUITCMENIS rununu neen A pis 23 8 2 3 Electrical and electronic requirements ss 23 8 2 4 Maintenance TequiVenierits vcsisess istics esi ee ERE ee SERERE ERE SHEER Nee t semis es sde einen ee ses teintes et 23 6 2 5 Light scattering uide uae Dee ae ean Pe EE cete 23 Dir SAMS A E TO 23 9 1 PERFORMANCE REQUIREMENTS ccccccccsssssseccccccecaussseeccceeeeasuseeeccceeseuunseeccccesseuaeseeecceseesauaasececeeessaaaneeceees 23 9 2 FUNCTIONAL REQUIREMENTS sccccccccccssssseecccccecasssseecccccecaasssececcceeseauaseecccesesauauseeccesessuuaaeeecceesssaauaeeesees 23 10 MCAO STREHL RATIO BUDGET eee e eene ne eee eee ette etn nao e eese t etna asses eese teens sees esee esee en asses eese eaa 24 Page 5 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements 1 Purpose of this document This document the Functional and Performance Requirement Document FPRD defines first the scientific requirement of the Gemini Multi Conjugate Adaptive Optics MCAO These requirements coupled with the system operational concepts detailed in the Operational Concept Definition Document OCDD are translated in the current document into technical and functional requirements The purpose of the MCAO FPRD is to provide engineers with the requirements on which to base the MCAO design It also provides guideline for the future users to understa
33. t of loss of electrical power 5 2 2 Timeto function REQ FPR 0102 Individual MCAO mechanisms should be set within 30s and a complete mechanical reconfiguration of the instrument should be achieved in 1 min 5 2 3 Thermal tolerance REQ FPR 0103 The optical benches should be thermally stable enough so that the need for recalibration is not driven by the opto mechanical bench but by other elements like e g deformable mirrors 5 2 4 Metric dimensioning REQ FPR 0104 Metric dimensions will be used in the MCAO system 5 2 5 Metric dimensions on drawings REQ FPR 0105 Metric dimensions in millimeters will be used in all as built drawings with dimensions called out to 0 01mm Page 11 of 24 07 11 01 M C AO MCAO Functional and Performance Requirements GEMINI 5 2 6 Metric fasteners REQ FPR 0106 All screws bolt nuts tapped holes and fasteners will be of standard metric size and called out as such on the as built drawings 5 3 Control system requirements 5 3 1 Operability REQ FPR 0201 All MCAO motions e g NGS probes science path ADC NGS ADC s LLT deployment Laser shutters Laser functionality AO control loop operations and other controllable features of MCAO will be controllable by computer through the standard EPICS control paths from the Instrument Control System 5 3 2 Configuration time REQ FPR 0202 The configuration times for various operations are listed below Table 1 Operational ov
34. tem Control System MCAO Multi Conjugate Adaptive Optics NGS Natural Guide Star OCDD Operational Concept Definition Document PSF Point Spread Function SALSA Safe Aircraft Localization and Satellite Acquisition system TT Tip Tilt 4 Operational Conditions 4 1 Atmospheric conditions The guidelines for the MCAO system performance assume a standard set of conditions This includes the atmospheric conditions the telescope performance and the optical aberrations in the science instrument This section outlines the nominal conditions for these components Median atmospheric conditions are assumed These conditions are summarized in the following table r O 0 55 um 0 O 0 55 um L 0 55 um To Median Conditions 16 5 cm 2 2 36m 5ms 4 2 Wind Shake For median wind conditions 8 4 m s wind speed at right angles to the enclosure slit the telescope wind shake power spectrum is assumed to be as follows McGonegal in Altair OCDD Morris Herriot and Davidge 1997 For f lt 6 4 Hz P 1 876e 14 0 3401 rad Hz For f gt 6 4 Hz P 1 876e 14 0 3401 6 4 rad Hz Page 7 of 24 07 11 01 N M C AO MCAO Functional and Performance Requirements GEMINI 4 3 Sodium Layer Content The figure below gives an example of sodium layer content over the year It was measured at 40 degrees North latitude The minimum is reached early in summer May June for values around 2 10 atoms cm An nal Meda
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