Functional Performance Requirements Document
Contents
1. 022000002 00aasasasasaaasa 20 MA DAL PUSA NONG ica icios 20 E SI iia epeneusnaeen sein tous A 20 De Ded SC TUT FACS N ER E O E A A 20 9 3 2 Command and ControL aaa 20 AI A eee ee ene eer ee eee eee eee 20 94 Data Procesin D cx apps 20 10 External Inte LACES nG GNG TINGNAN NANANA AA NAGA 22 IOA TO Oae IT La AA AA 22 10 1 1 Instrument Support Structure Interface oooccononncnnionnnnononnnonononnnnnnonnnnnonnnnnos Ze TOI Dry AI OTC octetos 22 LOA S alala AA PC 22 10 14 Cooling Water InterfaCE ie 27 10 1 5 Signal Control and Data Interfaces ooooooonnnnnonnnnnnnnnnncnnnonnnnnnnnnnnncnnnononnnnnos 22 DA ADA VE AP PA amet ee Zo Andrew Sheinis Page 4 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 11 Environmental Requirements ccsccccscccssscsssccsssccssccsssccsscccssccsssccssccssscesssceess 23 PTT AAAI EVV PP A 23 11 1 1 Transportation OCS ie 23 IA SOPAS ANUA ee eee RA 23 DAA CHAT OU ZULU OCS oia 23 11 2 Temperature EVI ONIVCN A a ANA 23 1 2 1 Operational FNVITONINGNE AN 23 YI AOL A SA RO Ee A A 23 11 2 3 Transport Environment ri Kanan nG KA DA 23 EREE IBA AAA 24 L14 Vacuum Environment sssrini ant 24 llad Creatine TC VACUUM re orense IEEE NEEE ONSEN ENUEN DEEN EENDERS 24 11 4 2 Vacuum Quality and DUP GU OD ar iaiicii 24 IESIMecHaniCaENIION Md E SSES 24 LDL Telescope Slew Rates aia 24 NOREEN EE 25 FE DOCU AAA 25 LAS SCS VIA occidente icon eacrd ta 25 12. 12 1 5 Drawing Standards All drawings shall comply with SALT approved standard 12 1 6 Drawing Numbering System All drawings shall be numbered in accordance with SALT instructions 12 1 7 Drawing Filing System Drawings will be maintained in electronic format Final drawings will be converted to PDF format and paper based print outs will be produced when necessary A database of drawings will be maintained in Microsoft Access format Notes and Comments 1 Final released drawings will be maintained by UWAST 2 The software applications needed to access or read the electronic versions includes Solidworks version 2009 12 2 Training The RSS NIR development team shall provide training documentation and a training course to SALT operations personnel on the operation maintenance and repair of RSS NIR 12 3 Reliability RSS NIR shall be designed and built to be reliable Andrew Sheinis Page 25 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 12 3 1 Downtime RSS NIR will have a downtime of lt 5 scheduled time on the telescope and where possible component failure shall result in gradual performance degradation 12 3 2 Spares Single point failures that may result in significant downtime shall be determined and where necessary critical spares shall be identified 12 3 3 Continuous Duty RSS NIR shall be designed and built for continuous operation Modules containing moving parts e g
3. and a scale of 0 233 pixel in the spatial direction 4 1 4 Spectral Resolution RSS NIR will deliver spectral resolving powers of 7000 per arcsecond in each of the J and Hshort bands 4 1 5 System Sensitivity RSS NIR should be capable of detecting unresolved sources with a J band magnitude of 20 2 and in the Hshort band with a magnitude of 18 7 in 3600 s with a SNR of 10 per resolution 4 1 6 Scattered Light Level The total amount of scattered light illuminating the science detector must be lt 2 of the total amount of light entering the RSS NIR instrument 4 1 7 Focusing Optics Ghost Images Ghost images generated in the RSS NIR optics must be at a level below 5 X 10 at radii gt 2 from the parent image 4 1 8 Polarimetry RSS NIR will have the capability to acquire stokes parameters of a TBD mag source at TBD percent polarization in 3600 s Andrew Sheinis Page 9 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 4 1 9 Calibration An array of slits will be supplied for calibration purposes in the Focal Plane RSS NIR will derive artificial calibration sources from the facility SALT Calibration Unit which will need to be equipped with the following PenRay lamps Ar Hg Xe Ne Kr See RSS NIR ICD 4 2 Image Quality and Optical Tolerances 4 2 1 RMS spot size The increase in total RMS spot size of the NIR beam due to wavefront error introduced by the RSS NIR portion of the spectrograp
4. Detector Requirements 5 2 1 Detector Format RSS NIR shall be designed to use a HgCdTe science detector array with a format of 2048x2048 with 18 um square pixels 5 2 2 Characteristics The RSS NIR shall be designed to take the fullest possible advantage of an HAWAITI 2 HgCdTe detector with the following characteristics a Number of pixels 2048 H x 2048 V b Architecture 4 independent 1024x1024 quadrants c Pixel size 18 um square d Effective fill factor 90 e Maximum frame rate 1 frames 0 33 seconds f IR material HgCdTe g Full well gt 65 000 electrons at optimum bias h Wavelength range 0 8 to 1 7 um 1 Nominal operating temperature 120 K j Dark current lt 1 electron second goal 0 01 electron second k Read noise lt 20 electrons rms goal 5 electrons rms 1 Quantum efficiency gt 50 0 8 to 1 7 um 5 2 3 Mechanical Interface The detector shall be mounted such that once adjusted it can be removed and reinstalled without necessitating optical realignment Andrew Sheinis Page 12 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 5 2 4 Thermal Interface The science array will be thermally coupled to the cold head by high thermal conductivity material The detector shall be maintained at operating temperature by an actively controlled electric heating element 5 2 5 Optical Interface Means will be provided to measure the science detector defocus e
5. List of Acronyms FPRD Functional and Performance Requirements Document RSS Robert Stobie Spectrograph NIR NIR ICD Instrument Control Document ICS Instrument Control System UWAST UW Madison Astronomy Department PAYLO Instrument Support Structure AD OCDD Operational Concept Definition Document OCS Observatory Control System TCS Telescope Control System Andrew Sheinis Page 28 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 13 2 Requirements Tabulation The following table shows the progress towards meeting the requirements at each of several milestones Notes and Comments TBD The requirement has not been fully defined yet UWAST Des The requirement should be met by UWAST design UWAST Des The requirement will be met by fabrication phase adaptation of UWAST design Des The requirement is met by the current state of the design RSAA The requirement is met by RSAA design and manufacturing procedures TOC A table of contents has been prepared for this manual Doc A draft document has been prepared SALT The requirement is to be met by extensions to the SALT Observing Tool OK SALT has supplied the required information No The current state of the design does not meet the requirement O O PPR f PR lupon a 4 Tests Tests T3 Cc O IA Wavelength Coverage ol SpatialResolution po FieldofView distortion P Stren Ratio Spectral Resolution Sy
6. Mechanical and Thermal Tolerances Where adequate mounting precision cannot be provided by dead reckoning convenient means will be provided to measure the misalignment of optical components of the spectrograph under ambient conditions and then adjust their alignment with a precision that allows the optical performance specification to be met Where thermally induced misalignment is significant theoretically derived compensation will be applied 6 3 Thermal Performance 6 3 1 Temperature Gradients Thermal effects due to temperature gradients outside the cryostat and pre Dewar inside the cryostat and near the detector shall be considered in the design of RSS NIR Realistic limits will be set according to performance requirements 6 3 2 Thermal Transients Thermal transient effects during cool down or warm up shall be considered in the design of RSS NIR Realistic limits will be set according to the performance requirements 6 4 Space Requirements RSS NIR shall be designed to fulfill the space requirements as specified in the instrument ICD 6 4 1 Electronic Enclosures All RSS NIR electronic enclosures mounted on the payload shall be counted in the space requirements given above 6 4 2 Access to Electronic Enclosures The electronic enclosures shall be accessible without removing RSS NIR from the PAYLOAD 6 4 3 Access to SALT Facility Glycol Ports SALT facility glycol ports on RSS NIR shall be accessible without removing the instrumen
7. P Vacuum Pump Capacity Vacuum System Operating Proc J Vacuum System Test Set up ooo Mechanism Safety oo Metric Dimensioning Ol Metric Dimensions on Drawings po Metric Fasteners Repeatability of Configuration Jo po Instrument Handling lo Control System Operability Oo ooo Configuration Time Oc ol Impactom Mechanism Accuracy Impacton Science Performance Temperature Control o Detector Temperature o pp Optical Elements Temperature o o o Rate of Temperature Change poo Speedingthe Warmingup po ET ME O O Andrew Sheinis Page 31 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison Requirement Description CDR Integration Acceptance Tests Tests Grounding and Shielding SO Electrostatic Discharge pNotUsed IE ISS S o NotUsed AAA Surface Temperatures Ol oo o y oO Not Used re po NotUsed S O Interfaces to SALT System SALT Supplied ICDs po re PAYLOAD Interface Mounting Plate Material o o jlo po Fasteners lo lo lo pd Optical Feed EOS llo HY Andrew Sheinis Page 32 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison oo E S pT Vacuum Interfaces lo pd Dry Air Interface olo lo lo rr ee SS HY aaa IN E ay COO M ay SS Transportation Altitudes Stora
8. thermal emission from that surface Nonetheless RSS NIR shall be deemed as having satisfied stray light and ambient background levels with a clean entrance window as well as clean telescope optics feeding the spectrograph 4 4 Throughput 4 4 1 System Efficiency in VPH Mode RSS NIR will have a total system throughput of the NIR portion of the beam over its required wavelength range of 40 at peak blaze and 28 at the edge of the order if SolGel coatings are used and 35 at peak blaze and 25 at the edge of the order if conventional AR coatings are used including grating dichroic and filter losses Andrew Sheinis Page 10 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 4 4 2 Filters RSS NIR shall have a bay of 12 filters which will be changeable with no impact to the optical system during the daytime operations support 4 5 General Optical Requirements RSS NIR shall meet the general optical requirements listed below 4 5 1 Cold Stop RSS NIR shall provide a cold stop operated at the ambient temperature of the pre Dewar 40 C nominal at or close to an image of the telescope pupil the primary mirror 4 5 2 Coatings The characteristics of all optical coatings shall be specified in design documentation All coatings shall be unaffected by repeated thermal cycling over the operating storage and transportation temperature ranges 4 5 3 Pre Dewar Thermal Environment All pre Dewar optical com
9. 2 1 2 Service and Calibration Manual 1002 7 7 77aa aaa 23 12 1 3 Software Maintenance Manual 227000007 m aa a 29 lat AS UL DOTS oe E AE RN 25 RL INANI TOS a 25 12 1 6 Drawing Numbering Ni 23 12 1 7 Drawing Filing System 01 a 2J A A 25 TD O o NADU CR II AA AA 25 IAS 26 DZD A A O A A 26 HD COMO US LIU rates 26 12 4 Maintainability and Servicead lity ccccccccscccccsssccccsssccccssscccccssccccsssccccssccceescesseeses 26 124 Standard COMPONCHIS sesers rororo a OEO 26 DD a MOU U A 26 AA A eee E E E E EE E 26 LIA AN T ate scree E AEE EEA E AEAEE E EEEE 26 12 4 5 Relative Equipment ATrangements occoooncnnnnonnnnnnonnnnonnnnnonnnononnnnnnnnnnnnnnnnnnnnnnos 26 E EE AAA 26 TAS DICE 26 A SO 27 12 6 1 Toxic Products and Formulations 0022 7 aa 27 12 7 PCCW OMG OTIC C OU E iodo Zi 12 7 1 Electromagnetic Radiation Generation 2 00 227 aaaa aa a7 12 7 2 Susceptibility to Electromagnetic Radiation ooooooonccnnnnncnnnnnnnnnnonnnnnnnonnnnnos 27 Andrew Sheinis Page 5 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 1240 V OF MARS MD ta Z AA NY BA AA AA 27 L IOT iman POI CN Oi E EE EE EA 2 13 PRD CM ICO iia 28 Tb LISTO ACTOS ta iii 28 132 Requirements Tabulation sssrinin E E E ai 29 Andrew Sheinis Page 6 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 1 Purpose The SA
10. 2 hours or less The RSS NIR Pre Dewar cooling system shall have the capability to cool the instrument from room temperature to operating conditions in 2 5 hours or less 6 6 2 Warm Up Time RSS NIR shall not require more than 7 2 hours to warm up the entire instrument from operating conditions to room temperature 6 6 3 Thermal Stability of cryogenic Dewar The surface on which the dewar optical system is mounted shall have a passive temperature control system providing a variable temperature to be referenced to the center of the cold work surface between 100 K and 140 K with a stability of 1 0 K The RSS NIR detector assembly shall have an active temperature control system providing a variable temperature to be set at the optimum temperature for the detector between 100 K and 140 K with a stability of lt 0 1 K 6 6 4 Thermal Stability of Pre Dewar The interior volume of the Pre Dewar in which the optical system is mounted shall have an active temperature control system providing a variable temperature to be referenced to the center of the cold work surface between 33C and 40C with a stability of 0 5 K Andrew Sheinis Page 15 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 6 6 5 Vibration Adequate measures shall be taken to ensure that the use of cryogenic closed cycle coolers shall not introduce sufficient vibrations into the mechanical structure to prevent meeting all rigidity alignment
11. CAR cold frame On the attachment of the coldstrap from this cryocooler to the cold work surface On the edge of the cold work surface furthest removed from the cryocooler cold straps On the getter assembly which is connected to the second stage of the cryocooler which is not used to cool the science detector 8 On the filter wheel motor eet A 8 3 2 Temperature Sensor Interfaces The temperature sensor read out interface shall be part of the Engineering Interface as described in 9 3 Notes and Comments 1 RSS NIR electronics temperature is monitored by the SALT thermal enclosure system Power to the thermal enclosures will be cut if the temperature exceeds 50 C Andrew Sheinis Page 19 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 9 Software Requirements 9 1 Software Design Requirements RSS NIR shall be a conforming instrument in that 1t shall use Labview and conform to SALT software and control system standards and the requirements listed below 9 1 1 Use of RSS VIS Controller Software Package The RSS NIR software engineers shall be guided by the SALT furnished RSS VIS Instrument Control System ICS 9 2 SALT Furnished Software SALT shall furnish a complete and final set of all Interface Control Documents and shall provide updates as they become available 9 3 Engineering Interface RSS NIR shall provide a means for command and control of RSS NIR mechanisms and science array contr
12. Characteristics OO HO Noa poo Detector Mechanical Interface J Detector Thermal Interface Detector Optical Interface lo o Detector Electrical Interface Detector Controller fl Detector Controller Mech IF Detector Controller Thermal VF gt OWS Detector fl Andrew Sheinis Page 30 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison Requirement Description CDR Integration Acceptance A A A ee OINWFSDetectorController ___ _______ _____ oo OIWFSDetContMeehWVF__ gt o ODWFS Det Contr Thermal F po OIWFS Detector Optical VF ___ ____ _ po OIWFS Detector Electrical VF pL Cold Stop Alignment e Movementof Spectra PO O ME IO O ma S ME O E MechandThermalToleranees oo o Temperature Gradients oo ThermalTransients o Space Requirements ElectronicEnclosures Accessto ElectrEnclosures oo Aceessto Vacuum Ports o o Access to Cooling Water Ports CT pf AccesstoDry Air Ports o Mechanical Comnections J Po TotalMas OO oo CenterofGravity o Balance Tolerance po BallastWeight Spectrograph Thermal Stability o To o Cool Down Time A E O WarmUpTime Ol loo Detector Thermal Stability ooo Vibration Vacuum System Holding Areas
13. DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 475 N Charter Street Madison Wisconsin 53706 1582 Telephone 608 262 3071 FAX 608 263 6386 www astro wisc edu http www astro wisc edu Date FUNCTIONAL AND PERFORMANCE REQUIREMENTS DOCUMENT Andrew Sheinis University of Wisconsin at Madison Astronomy Department Revision History Revision No Author Approval amp Description Date Date Revision 1 Andrew Sheinis Original document July 7 2008 Page 1 of 34 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison Contents AA AA AA AA AA 7 2 Applicable DOCUS ie 7 SrO NO ri oe cuca 8 AAA o A 9 4 1 Science NO AA 9 Ca AA 9 dd aa CHAO apcere seis cca eas os asec eae EE 9 4 1 3 Spatial Resolution ii 9 AA ARA E E 9 ASI AO AAA e E E E E T 9 4 1 0 Scalered LoM LEVEL A a 9 dd MOS AA 9 EEE e EOE AES E EN E E ENE EEE N 9 A AA 10 4 2 Image Quality and Optical Tolerances ccccsesccccssscccssssccccesscccssssccccssccccescccseeses 10 ELIAS OL SO AA 10 E OTN A 10 A sd 10 LI Baf AAPP PP AA Error Bookmark not defined 4 3 1 Optical BAf lINZ ooononnnnnicnnnnncnninononnnoncnnnnnnonnns Error Bookmark not defined 4 4 Internal Instrument Background ccccccccrscccsssccsssccsscccssscccsssccsccccsssccesscceesccsessees 10 4 4 1 System Emissvity aa a Error Bookmark not defined 4 4 2 Background due to Dust on Entrance Window 2 0000200000masassgaas
14. LT Robert Stobie Spectrograph NIR RSS NIR Operational Concept Definition Document OCDD DOCNUMBR defines the scientific requirements of the RSS NIR instrument and describes operational scenarios These are translated into technical requirements in the RSS NIR Functional and Performance Requirements Document FPRD Other technical requirements for SALT facility instruments derive from the RSS NIR Conceptual Design Study Statement of Work The scientific and technical requirements are summarized in this FPRD and their relationships are identified so that all functional and performance requirements can be traced from top level science requirements The two purposes of the RSS NIR FPRD are to provide the SALT scientific community with an understanding of what RSS NIR will do and how quickly or how well it will do it and to provide engineers with the requirements on which to base the RSS NIR design 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 RSS NIR should be traceable to a requirement in this document and there should be no features of RSS NIR that are not required by this document RSS NIR will be designed in stages with a review after each stage 1s complete Comments from the review committee will be folded into the design so the requirements will change as the design changes Therefore thi
15. View Mode and Observe Mode reformatted images of the sky will be specified by a central wavelength in microns and a spectral range in either microns or velocity in km s The View Mode and Observe Mode extracted spectra will be specified by a central x y pixel coordinate in the image of the sky a circular aperture radius in pixels a sky annulus inner radius in pixels and a sky annulus width in pixels Acquisition and display of data obtained in View Mode will be defined by a set of View Mode parameters detector read out method integration time number of coadds number of Fowler samples Non Destructive Read NDR period number of NDRs image subtraction flag subtraction image file name image compression region central wavelength image compression region wavelength range continuum spectral region central wavelength continuum spectral region wavelength range extracted spectrum x y center extracted spectrum aperture radius extracted spectrum sky annulus inner radius extracted spectrum sky annulus width Acquisition and display of data obtained in Observe Mode will be defined by a set of Observe Mode parameters detector read out method integration time number of coadds number of Fowler samples Non Destructive Read NDR period number of NDRs image subtraction flag subtraction image file name image compression region central wavelength image compression region wavelength range continuum spectral region central wavelength co
16. abricated tested delivered and commissioned by the UW Madison Astronomy Instrument group for use on the SALT 11 m telescope The SALT 11 m telescope is designed to achieve the most light gathering capability for the smallest cost primarily for spectroscopic science A high throughput moderate spectral resolution near infrared spectrograph F P imager and spectropolarimeter has been identified as a desirable complement to RSS VIS in order to realize the scientific potential the SALT telescope RSS VIS was a fast tracked instrument that 1s intended to provide this capability on the shortest possible timescale and at low cost the RSS NIR NIR beam is an upgrade to the Visible beam that was planned from the beginning With the exception of X shooter on the VLT RSS NIR will be unique among instrumentation for 8 10 meter class telescopes in its ability to simultaneously record data in the visible and NIR It will open a new window for the discovery and study of the most distant and earliest galaxies in the universe The RSS NIR upgrade will specialize in very high throughput low to medium resolution spectroscopy narrow band Fabry Perot imaging and spectropolarimetry over 0 8 to 1 7 microns with at least one mode covering the entire wavelength range simultaneously The design includes an articulated camera Volume Phase Holographic VPH gratings and a single etalon Fabry Perot system This is an opportunity to produce a unique instrument at relativ
17. and shall be capable of withstanding shipment among Madison Capetown and Sutherland 11 5 1 Telescope Slew Rates RSS NIR shall be capable of withstanding slew rates of 2 per second in combination with rotation of the rotator to maintain alignment with the parallactic angle as it changes at these slew rates All optics and mechanisms shall meet their flexure and alignment specifications at these rates Notes and Comments 1 The rotator requires faster slew rates than specified for maintaining parallactic angle Andrew Sheinis Page 24 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 12 Other Requirements 12 1 Documentation RSS NIR shall be delivered with adequate documentation to facilitate the operation maintenance and repair of the instrument 12 1 1 User s Manual The Users Manual shall be written to enable a new user of RSS NIR to easily get acquainted with the operation of the instrument 12 1 2 Service and Calibration Manual A manual shall be written to enable SALT technical support personnel to maintain RSS NIR This manual shall include documentation to describe the observations required to allow spectral and spatial calibration of RSS NIR data 12 1 3 Software Maintenance Manual A Software Maintenance manual shall be provided to enable SALT software maintenance staff to maintain the RSS NIR software 12 1 4 As Built Drawings The as built drawings shall be as specified in section 6 10
18. asasaaaans 10 BD PV OU CIE saen naO NANG sc sacdesuseonsss EE A N N N E 10 4 5 1 System Efficiency iio 10 TLT AA 11 4 6 General Optical Requirements as Il BOGE COOL O AA APA 11 20 A ANA o A E E 11 4 6 3 Pre Dewar Thermal Environment 10 2 aaa 11 TENA 11 Tama AP AR AP NAP 11 Detector Requirements cornada 12 5 1 Science Detector Performance Requirements cc0000000 e e e 12 Sd Detector Kedd NOISE ANA NAAN E E NASA GORG 12 pA OMIT AA PAPA 12 A TY EREA AA EEE EA EEA A siete E E 12 Andrew Sheinis Page 2 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 5 2 Serene Detector Requirements ia 12 E DE TOF AAA 12 AA E T E E 12 32 3 Mechanical IMI tte BA 12 5 2 4 NA AM 13 Di OC INEA O ios NA O 13 A VCCI CN ACV AA 13 ds NONG Detector C OFO CP NAA eel 13 Di Dk IVE COICO A 13 6 Mechanical REGTIKEPICD IS 2NA GANA 14 a UY AAA AA AA AA E 14 6 1 1 Alignment of the Instrument to the Telescope Optics gaan 14 6 1 2 Movement of Spectra on the Detector 2 000200000aaaaasaaaaaasaaaaasaaaaasaaaana 14 6 2 Mechanical and Thermal Tolerances ccccsssccccssscccsssscccsesccccssscccccssccccsscccsessccoees 14 03 Thorma Per OVINE is 14 6 3 1 Temperature Gradients ada da idad it 14 0 2 MERMA T FONS V trote tono 14 GA PACE REGUN OMENS ada 14 A a AA 14 6 4 2 Access to Electronic Enclosures oonccooonnnncconnnnnnonononononnnn
19. col supply and return for electronic enclosures and any other use through the connectors provided on the payload 10 1 4 1 Number of Plumbing Connections RSS NIR shall have one glycol supply connection and one return line connection for the portion of the instrument on the payload RSS NIR shall have appropriate tees from these lines to serve all instrument payload needs 10 1 4 2 Resistance to Glycol The glycol lines and connectors shall not be damaged in any way when used with a cooling solution containing ethylene glycol 10 1 5 Signal Control and Data Interfaces RSS NIR shall receive and provide all signal control and data paths through the connectors provided on the payload 10 1 5 1 Number of Signal Control and Data Connections RSS NIR shall have one connection for the entire instrument to the appropriate Cassegrain Rotator Utility Box for each of the following 1f needed Circuit Connector Type Cable Instrument Cable Connector Wrap Andrew Sheinis Page 22 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison RSS NIR shall have appropriate tees from these lines to serve all instrument needs In out signals marked with must be bridged at the cable wrap connector plate when not connected to instruments 10 1 6 Dry Air Interface RSS NIR shall derive dry air for flushing the cryostat window from the supply line on the payload as per the instrument ICD 10 1 6 1 Number of Air Line Connection
20. cryo cooler cold heads shall be designed or selected to meet the ICD assuming continuous operation 12 4 Maintainability and Serviceability RSS NIR shall meet the SALT requirements for maintainability 12 4 1 Standard Components Wherever possible RSS NIR shall use unmodified commercially available standard components 12 4 2 Modularity To the extent possible RSS NIR shall be designed to be modular 12 4 3 Access Access to components and subassemblies shall be considered in the RSS NIR design particularly for those elements that are accessed frequently Tool and hand clearances shall be considered as well as space required to remove modules visual access to components or a means to feel their correct position and alignment e g for electronic connectors 12 4 4 Alignment Alignment of optical components shall be achieved to the greatest extent possible by accurate machining of locating fixtures 12 4 5 Relative Equipment Arrangements Equipment shall be located with due consideration of the sequence of operations involved in maintenance procedures To the greatest extent possible the most accessible locations shall be reserved for the items requiring most frequent access 12 4 6 Handling Modules greater than 15 kg in mass shall have suitable handles for use in removing replacing and carrying them Handles shall be located such that the vector sum of resultant handling forces shall pass close to the center of gravity of t
21. e e ee e 17 7 3 1 Impact on Mechanism AccuraCcy 00 27000aaasasaaaassaaasasaaaasssasas sarsa 17 7 3 2 Impact on SCION PENA is 17 Tp Lemperalire Controla ces 17 14d Detector Temperatur its 17 7 4 2 Cryogenic Dewar Optical Elements Temperature ooooconnoncnnncnnnnnnnonnnnnnnnnnnnnns 17 7 4 3 Pre Dewar Optical Elements Temperature 17 7 4 4 Limiting Rate of Temperature Change cryogenic DeWAT oooooooccccncnoccnccnncnncnno I7 7 4 5 Limiting Rate of Temperature Change Pre Dewar oooooconconccnninocnncnonnnnnnncnnnnnos 17 7 4 6 Speeding the Warming Up Change cryogenic Dewar oooooocccnnocccincnoconcnnacnnnnnns 18 7 4 7 Speeding the Warming Up Pre DeWadTr ooooooonncnnnoncnncoonnnnnnnnnnnnnnnnnnnnnnnnnnannnnnnns 18 8 Electrical and Electronic Requirements ooccccocconoccnncccnocccnoconocccnocccncccnocccnaconicccnocos 19 o 1 Electronic Design Requirements exe iscscnccsnsteencssnasensduuseaquaceatenstenessesessiseaetestiansessssenss 19 Oud Grounding and Shielding saiscuicaxrsmabictiaasoisiomabichiaeeiorsaltitiaboaenabehiaeaateen 19 A ls DISCOV a 19 0 2 Cable Vrap Inir GG Na daa is 19 NARDI A AA AA 19 8 3 1 Temperature Sensor Locations 22000000 aasa 19 8 3 2 Temperature Sensor Interfaces 7 0 00 maassanaaaaasanaaaasasanaaaasssnaassssssasass 19 9 Software Requirements 230i RG GAGANA 20 9 1 Software Design Regrann Napa riales 20 9 1 1 Use of RSS VIS Controller Software Package
22. e University of Wisconsin Madison 7 Control System Requirements RSS NIR shall meet all general control system requirements given below 7 1 Operability Filter and grating change mechanisms and other controllable features of RSS NIR shall be controllable by computer through the standard LabView control paths from the Instrument Control System 7 2 Configuration Time The control system overhead on the mechanism configuration times shall be such that the total RSS NIR configuration time is within the limit set by section 6 8 2 7 3 General Control System Requirements 7 3 1 Impact on Mechanism Accuracy The control system for RSS NIR shall be designed so that the accuracy of the controllable mechanisms is not limited by the performance of the control system 7 3 2 Impact on Scientific Performance The control system shall not impact on the scientific performance of RSS NIR In particular attention shall be given to the impact of the control actuators and sensors on the thermal regime of the instrument including their thermal radiation 7 4 Temperature Control The control system shall control the temperature of the detector SIDECAR and the optical elements 7 4 1 Detector Temperature The control system shall regulate the detector temperature as specified in section 6 6 3 7 4 2 Cryogenic Dewar Optical Elements Temperature The design of RSS NIR shall provide for optical elements in the cryogenic dewar to be temperature stabiliz
23. ed by heat sinking to a cold plate which is temperature controlled by the control system 7 4 3 Pre Dewar Optical Elements Temperature The design of RSS NIR shall provide for optical elements in the pre Dewar to be temperature stabilized by convective cooling of an inert dry gas or dry air 7 4 4 Limiting Rate of Temperature Change cryogenic Dewar If the thermal characteristics of RSS NIR introduce extreme rates of temperature change on cooling down the temperature control system shall limit the rate of change at the detector to 0 5 K per minute 7 4 5 Limiting Rate of Temperature Change Pre Dewar If the thermal characteristics of RSS NIR introduce extreme rates of temperature change on cooling down the temperature control system shall limit the rate of change in the Pre Dewar to 0 5 K per minute Andrew Sheinis Page 17 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 7 4 6 Warming Up of the Dewar If the thermal characteristics of RSS NIR are such that warming up by turning off the cryo coolers will not meet the requirement in section 6 6 2 the temperature control system shall actively heat the detector and the cold plate to speed the warming up so that RSS NIR meets this requirement but the rate of change of temperature shall be limited to 0 5 K per minute 7 4 7 Warming Up of the Pre Dewar If the thermal characteristics of RSS NIR are such that warming up by turning off the Pre Dewar chiller will not m
24. eet the requirement in section 6 6 2 the temperature control system shall actively heat the Pre Dewar to speed the warming up so that RSS NIR meets this requirement but the rate of change of temperature shall be limited to 0 5 K per minute Andrew Sheinis Page 18 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 8 Electrical and Electronic Requirements 8 1 Electronic Design Requirements 8 1 1 Grounding and Shielding 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 8 1 2 Electrostatic Discharge The RSS NIR design shall protect sensitive components from electrostatic discharge 8 2 Cable Wrap Interfaces The requirements on the electrical and electronics interfaces with the cable wrap are included in the instrument ICD 8 3 Temperature Monitoring In addition to the sensors for temperature control temperature sensors are required to monitor the cryogenic environment within the Dewar s vacuum jacket and at the detectors These will be used to tune the thermal regime of the instrument and for maintenance purposes 8 3 1 Temperature Sensor Locations Auxiliary temperature sensors will be located as follows On the cold head of the cryocooler inside of the Dewar On the attachment of the coldstrap to the detector heater block On the detector cold frame On the SIDE
25. ely low cost because it leverages the considerable effort and expense undertaken by UW researchers and others for the visible system while preserving all of the visible capability RSS NIR has passed a Conceptual Design Review CoDR held in Capetown South Africa on May 7 8 2006 which resulted in full endorsement of the instrument from the SALT Board of Directors who represents all partners in the SALT consortium In addition RSS NIR has passed a Preliminary Design Review PDR held in Madison Wisconsin on July 18 19 2008 At that time the review panel recommended that the instrument have a Midterm review prior to placing orders for most of the large capital items In order to prepare for the MTR the preliminary spectrograph design was completed primarily at UW The pre construction optical design was completed by optical designer Professor Harland Epps from the Univ of California A preliminary performance model was developed by the PS to analyze the effects of thermal emission scattered light and operating temperature A preliminary mechanical design was developed collaboratively with the University of Wisconsin engineering staff At present this design team is analyzing critical risks and risk mitigation in advance of a Midterm Design Review scheduled in May 2009 Andrew Sheinis Page 8 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 4 Optical Requirements 4 1 Science Requirements The optical requiremen
26. ge Altitudes Operation Altitudes Operational Environment Survival Environment HY a Humidity Environment O Vacuum Environment Creating the Vacuum P Vacuum Quality and Duration _ Room Temperature Vacuum HY SS SS UU E HY A Mechanical Environment Documentation o Service and Calibration Manual o Software Maintenance Manual pi AsBuiltDrawings os Drawing Standards o Drawing Numbering System ooo Drawing Filing System A Training ME ll Cl Ready SS A Spares E E E q O ContinuousDuty ES MS E Maintainability SS ooo Standard Components JJ Transport Environment Andrew Sheinis Page 33 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison Requirement Description CDR Integration Acceptance A A A aaye Modularity po ooo o poo Access Alignment SS Relative Equipment Arrangemnt Subassemblies Handling ooo S Human Engineering po Lifetime Andrew Sheinis Page 34 of 34 05 13 09
27. h a combination of Quick Look Displays and the Data Handling System data pipeline Separate View Mode and Observe Mode Quick Look Display channels will be maintained Andrew Sheinis Page 20 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison View Mode data will be processed for display by the Detector Controller and displayed in the View Mode Quick Look Display but will not be archived Observe Mode data will be processed for display by the Detector Controller and displayed in the Observe Mode Quick Look Display and the raw data will be archived The View Mode and Observe Mode Quick Look Displays will display the detector image a reformatted image of the sky compressed in the spectral direction and a sky subtracted spectrum extracted from a specified position within that image Separate pre recorded images will optionally be subtracted from raw data by the Detector Controller before display in the View Mode and Observe Mode Quick Look Displays The image compression region of the View Mode and Observe Mode reformatted images of the sky will be specified by a central wavelength in microns and an image compression spectral range in either microns or velocity in km s The compressed image of a continuum spectral region will optionally be subtracted from the View Mode and Observe Mode reformatted images of the sky by the Detector Controller before display The continuum spectral region subtracted from the
28. h optical system will be no greater than 10 um rms radius over the wavelength range of 0 8 to 1 7 microns in spectroscopic mode and no greater than 15 um rms radius in polychromatic J or Hshort band imaging 4 2 2 Alignment The ability to accurately align the instrument with the telescope is critical to minimizing background flux A means of establishing alignment of the cold stop to within 1 of the projected size of the primary mirror shall be provided Notes and Comments 1 This requirement does not necessarily lead to the inclusion of interactive alignment aids in the design Off telescope alignment together with a verification test could suffice 4 2 3 Focus A means to focus the NIR beam independent of the visible beam will be possible Nominally this will be a focus stage on elements L4 L5 in the camera alternatively this will be a focus stage on the detector 4 3 Internal Instrument Background 4 3 1 Thermal background Light Level The total amount of thermal background light at the science detector must less than the intra OH sky background at an R 7000 using one of the 3 wavelength cutoff filters 4 3 2 Background due to Dust on Entrance Window Although not strictly internal the contribution to instrument background from ambient temperature dust on the RSS NIR entrance window and other surfaces upstream can be significant The design calls for an enclosed purged space by the entrance window to the pre Dewar which mitigates
29. he unit 12 5 Lifetime RSS NIR shall be designed for an operational lifetime of 15 yr without a major overhaul Components likely to affect the lifetime requirement shall be identified Andrew Sheinis Page 26 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 12 6 Matertals 12 6 1 Toxic Products and Formulations No toxic products and formulations are required for the development construction and maintenance of RSS NIR 12 7 Electromagnetic Radiation 12 7 1 Electromagnetic Radiation Generation RSS NIR shall not significantly add to the electromagnetic radiation of 1ts operating environment 12 7 2 Susceptibility to Electromagnetic Radiation RSS NIR performance shall not be compromised by the existing electromagnetic radiation of its operating environment 12 8 Workmanship Standard RSAA workshop practices shall apply to workmanship in development and construction 12 9 Safety Normal considerations including compliance with applicable regulations shall apply in the areas of mechanical electrical and electrostatic safety 12 10 Human Engineering Human engineering considerations shall apply especially with respect to handling of system items required in readying RSS NIR for use on the telescope and its removal after use and in the design of the user interfaces Andrew Sheinis Page 27 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 13 Appendices 13 1
30. ntinuum spectral region wavelength range extracted spectrum x y center extracted spectrum aperture radius extracted spectrum sky annulus inner radius extracted spectrum sky annulus width The View and Observe Mode Quick Look Displays will be capable of processing and displaying data frames in less than 10s Andrew Sheinis Page 21 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 10 External Interfaces 10 1 Payload Interfaces 10 1 1 Instrument Support Structure Interface RSS NIR shall interface mechanically to the SALT Instrument Support Structure PAYLOAD through RSS VIS 10 1 2 Dry Air Interface REQ FPR 0606 RSS NIR shall obtain dry air and return low pressure air through the connectors provided inthe payload as specified in the ICD 10 1 3 Electric Power Interface REQ FPR 0611 RSS NIR shall derive its electric power through the connectors provided on the payload 10 1 3 1 Number of Electrical Connections RSS NIR shall have two electric power connections for the entire instrument One connection will provide clean power for the computer and electronics while the other will provide dirty power for the cryo coolers and fans The dirty connection should provide optional 220 Volt 3 phase power for the cryo coolers RSS NIR shall have appropriate runs from a junction box to serve all instrument power needs 10 1 4 SALT Facility Glycol Interface RSS NIR shall derive cooling SALT facility gly
31. oller and data capture from the science array without the need for having SALT control systems 1 e the Observatory Control System and the Telescope Control System present or connected 9 3 1 User Interface To the extent practicable the user interface in the Engineering Interface should appear to a user to be similar to the RSS VIS User Engineering Interface 9 3 2 Command and Control The Engineering Interface shall be capable of commanding and controlling all RSS NIR mechanisms and reading status from all RSS NIR sensors 9 3 3 Data Capture The Engineering Interface shall be capable of capturing data from RSS NIR Notes and Comments l Not all data readout modes need be supported The data that is captured may require extensive processing normally done by the RSS NIR Instrument Control System or the SALT Data Handling System to be intelligible There is no requirement for the Engineering Interface to perform this data processing which may be done off line on another system to analyze results The Engineering Interface may send de scrambled data to the DHS to be shown in a Quick Look Display 9 4 Data Processing The RSS NIR Detector Controller software will perform data processing and send the processed data to the SALT Quick Look Displays as well as the raw data to the Data Handling System On line data assessment will be provided for RSS NIR in accordance with the descriptions in the Operational Concept Definition Document throug
32. ononononcnnononanononnnninnns 14 6 4 3 ACCESS to COOLING Water Ports iia 14 6 4 4 Access to Dry AIP POS rt 14 OA Mechanical CONMCCIIONS ica E aaah 15 6 5 Mass and Center of Gravity RequirementS s sssssssssssossssossscossscossecossesossecossesossesose 15 Odd LOA M S ota 15 aa CT O GANI aNG AA eee ene ower ASAN 15 AA AA Error Bookmark not defined A A A 15 6 0 Cryogenic COOLING System ABANGAN A NAG 15 Baa COOL DOW AMO A ABALA AA O AA AS 15 O WOO LING aasa ene NAMAN AA AALANGAN 15 6 6 3 Thermal Stability of cryogenic Dewar 2 000020000aaaaasaaaaaasaaaasasasasasasaaas 15 6 6 4 Thermal Stability of Pre Dewar oooooonnnnnonnnnnnonnonononnnnnnnonnnnnnnnnnnnnnnonnnnnnnnnnnnnnnos 15 OOD Ai 16 O I dcui SUSTO ai EE ANA EE 16 O Ll Slapin ana OIR APS O E iioca 16 6 8 Operational Requirements for Mechanisms sccccrscccrrscccsssccrsscccssscccsscccsssccsssccseses 16 A 16 OZ LIME AAA sad 16 6 8 3 Repeatability of Configuration 0 0 3aassasaasaasanaaaassanaaaasssnaasssssssasass 16 ISAB LENA BA E NA E E A E E PA 16 AO Cana lag Dimensionini AA AAP AAP 16 6 10 1 Metric Dimensions on Drawings 2 0002000003 aa 16 Andrew Sheinis Page 3 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison A ri a A AG 16 7 Control System ROGU IV OMG INANGAT 17 sk OPEKADIN AABANGAN digo 17 iz CONSUMO LIM 17 7 3 General Control System Requirements c00000000
33. orted and stored in a wide range of humidity environments in the range 0 to 100 relative humidity with condensing moisture Notes and Comments l Operation of RSS NIR at high relative humidity levels may cause condensation on the Pre Dewar window Using heaters on the window or a hot air system are incompatible with the thermal management of the telescope Dry ambient temperature air will be provided in the PAYLOAD for window flushing 11 4 Vacuum Environment RSS NIR shall maintain a vacuum inside the cryostat 11 4 1 Creating the Vacuum REQ FPR 0708 RSS NIR shall provide a means to evacuate its cryostat while the instrument is on its handling rig in the instrument support area and while it is attached to the PAYLOAD 11 4 2 Vacuum Quality and Duration RSS NIR shall be capable of being kept cold and operated without measurable degradation of scientific performance for 6 months If needed the instrument shall be capable of being kept at room temperature without contamination of the detector or internal optics significantly affecting the scientific performance for at least 3 months without pumping Notes and Comments 1 Instruments will be pumped down in the instrument support facility then transported to the telescope 2 Operating vacuum may only be obtained with a cold instrument 11 5 Mechanical Environment RSS NIR shall be capable of operating in the mechanical environment of the SALT telescopes and their base facilities
34. ponents and coatings shall meet all performance requirements when operated at the pre Dewar operational temperatures nominally 40 C 4 5 4 Vacuum Environment All cryogenic Dewar optical components and coatings shall meet all performance requirements when operated in a vacuum of less than 10 Torr at operational temperatures down to 100 K 4 5 5 Thermal Cycling The performance of all optical components and coatings in the cryogenic Dewar shall not be degraded by repeated thermal cycling at a maximum rate of temperature change of 0 5 K minute Andrew Sheinis Page 11 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 5 Detector Requirements The RSS NIR detector systems shall conform to the following requirements 5 1 Science Detector Performance Requirements 5 1 1 Detector Read Noise RSS NIR should employ read noise reduction techniques such as linear fitting up the ramp to achieve an effective read noise of lt 20 e 5 1 2 Dark Current The RSS NIR detector should have a dark current lt 0 1 e s pix with a goal of lt 0 01 es pix 5 1 3 Stability 5 1 3 1 Bias Variations Over a period equal to the longest integration time of 3600 s bias variations shall be less than the read noise 5 1 3 2 Gain Variations Over a period equal to the longest integration time of 3600 s gain variations shall be less than the photometric stability of the atmosphere which is taken to be 1 5 2 Science
35. rror under operational conditions and then adjust the position of the science detector with a precision that is finer than that corresponding to the spatial resolution of the instrument 5 2 6 Electrical Interface The electrical interface to the detector is through a suitable connector 5 3 Science Detector Controller RSS NIR will use as the science detector controller the SIDECAR ASIC controller and the JADE 2 subsystem interface card both provided by Teledyne 5 3 1 Mechanical Interface The SIDECAR controller shall be mounted internal to the cryostat The JADE 2 controller interface card will be mounted on the cryostat external to the vacuum enclosure The power supply shall preferably be mounted in one of the near by electronics enclosures Andrew Sheinis Page 13 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 6 Mechanical Requirements 6 1 Rigidity RSS NIR shall be designed to be rigid and to meet all the requirements listed below 6 1 1 Alignment of the Instrument to the Telescope Optics The position of the RSS NIR cold stop with the primary mirror image shall be maintained to 1 10th the accuracy specified in 4 2 2 in any attitude of the telescope and rotator 6 1 2 Movement of Spectra on the Detector RSS NIR shall be designed so that flexure in the instrument shall result in the image of the spectra on the detector moving less than 1 pixel per any 1 hour integration of the instrument 6 2
36. s RSS NIR shall have one connection to the air supply for the entire instrument RSS NIR shall have appropriate tees from this line to serve all instrument dry air supply needs 11 Environmental Requirements 11 1 Altitude Environment RSS NIR shall be capable of being transported stored and operated in a wide range of altitude environments 11 1 1 Transportation Altitudes RSS NIR shall be capable of being transported at any altitude between 70 m and 4 200 m by any transportation mode RSS NIR shall be capable of being transported by commercial jet with pressurized cargo compartments at altitudes up to 15 km 11 1 2 Storage Altitudes RSS NIR shall be capable of being stored in or out of its shipping container at any altitude between 70 m and 4 200 m 11 1 3 Operation Altitudes RSS NIR shall be capable of being operated at any altitude between 70 m and 2000 m 11 2 Temperature Environment 11 2 1 Operational Environment RSS NIR operational temperature environment shall be limited to 10 to 25 C 11 2 2 Survival Environment RSS NIR shall be capable of surviving a temperature range of 20 to 45 C without damage 11 2 3 Transport Environment RSS NIR shall be capable of withstanding a temperature range of 20 to 50 C during transport without damage Andrew Sheinis Page 23 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 11 3 Humidity Environment RSS NIR shall be capable of being transp
37. s document will be updated as needed after each major design review to maintain the correspondence between requirements and design This current version reflects the status at the Conceptual Design Review 2 Applicable Documents po UWAST TE RSS NIRCODRO a sar RSS NIRCoDRreport a UWAST_ RSS NIRStatementofWork_________________ a Q gt jUwasr RSS NIR Operational Concept Definition Document _ oo QQ EPPS RSS NIR NIR Preliminary Optical Design EPPS O RSS NIR NR Preliminary Optical Design Appendices QQ UWAST_ SALT Software Design Description po SALT SALT Telescopes Optical Design Summary __________ o QQ SALT SALT telescope IQ summary __________________ pT SALT i Telescope to InstrumentsICD poo RSS VIS RSS VIS to RSS NIR NIR ICD SALT Interlock System to Science Instruments ICD po SALT Science Instruments to Data Handling ICD po sar Science Instruments to System Services ICD a SALT Instrument Components Controller ICD PY SALT Instrument Sequencer ICD a SALT On InstrumentWavefrontSensoriCD______________ a psarr SALT System Error Budget Plan po SALT SALT Electronic Design Specification et EF FTk I Andrew Sheinis Page 7 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 3 Introduction This document represents the current understanding of the capabilities and performance of the Robert Stobie Spectrograph NIR to be designed f
38. stemEfficiency System Emissvity Scattered Light pd GhostImages P ContrastRatio p Detector Read Noise P Detector Dark Current o LO a Mechanisms Time to Function po Notused P Downtime lo ooo Dataassessment View and ObserveModeOLDs Q View Mode data displayed J Observe Mode data displayed and archived BO Continuum subtraction Continuum subtraction specification Andrew Sheinis Page 29 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison Requirement Description CDR Integration Acceptance Tests Tests Spectra display specification oc p View Mode parameters olo lo Observe Mode parameters oc Ooo lo PE MTS TES TECOS MESS EE MESS S y o a aaa Ss SC Artificial Calibration Sources ol o y Polarimetry lolo lo System Sensitivity o ol llo P PointsourcesK23 ol lo po Notused lo loo lo pi Cold Stop Alignment oc Ol ol lo po Focus MES ME ES S po Noted MES EE FE S y o A Vignetting E e o Order Sorting Filters J O To o T y yoo Not Used HY HY CU HY CJ EAT cc m Coatingsand Thermal Cycling Not Used es ee EEN IEA Optical Components in Vacuum J oo fo Optical Comp Temp Cycling Detector Bias Variations ___ ____ Detector Gain Variations lo Pp DetectorFormat fo fo po NotUsed Detector
39. t from the PAYLOAD 6 4 4 Access to Dry Air Ports Dry air ports on RSS NIR shall be accessible without removing the instrument from the PAYLOAD Andrew Sheinis Page 14 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y The University of Wisconsin Madison 6 4 5 Mechanical Connections All subsystems on the RSS NIR shall be accessible without removing the instrument from the PAYLOAD with the exception of slit cooling 1f implemented 6 5 Mass and Center of Gravity Requirements RSS NIR shall meet all mass and center of gravity requirements listed in the instrument ICD 6 5 1 Total Mass RSS NIR including its support frame thermal enclosures electronics and all cabling and services connections that reside on the payload shall have a mass as defined in the ICD 6 5 2 Center of Gravity RSS NIR including its support frame thermal enclosures electronics and all cabling and services connections that reside on the payload shall have a center of gravity in all configurations on the port axis as specified in the ICD from the mechanical interface on the PAYLOAD 6 5 3 Ballast Weight A ballast weight and its supporting structure shall be supplied as required to meet the above requirements 6 6 Cryogenic Cooling System RSS NIR shall meet all cooling system requirements listed below 6 6 1 Cool Down Time The RSS NIR cryogenic cooling system shall have the capability to cool the instrument from room temperature to operating conditions in 7
40. tracking and other performance requirements 6 7 Vacuum System 6 7 1 Staging and Holding Areas RSS NIR will use the same vacuum system facilities in the staging and holding area as the RSS VIS 6 8 Operational Requirements for Mechanisms The RSS NIR mechanisms shall meet the requirements listed below 6 8 1 Safety No mechanism shall move in the event of loss of electrical power 6 8 2 Time to Function A complete reconfiguration of the instrument should be achieved in lt 1 min for 80 of the reconfigurations and lt 1 5 minutes for 100 of the reconfigurations 6 8 3 Repeatability of Configuration The total error at the detector resulting from reconfiguration of all mechanisms shall be less than 5 0 pixels 6 9 Instrument Handling The RSS NIR support frame shall have mounting points allowing the instrument to be lifted moved and stored free standing and attachment points for the SALT instrument handling facilities 6 10 Metric Dimensioning Metric dimensions and drawing conventions per ISO standards shall be used in RSS NIR 6 10 1 Metric Dimensions on Drawings Metric dimensions in millimeters shall be used in all as built drawings 6 10 2 Metric Fasteners All screws bolts nuts tapped holes and fasteners shall be of standard metric sizes and called out as such on the as built drawings except for off the shelf equipment required in the RSS NIR Andrew Sheinis Page 16 of 34 05 13 09 DEPARTMENT OF ASTRONOM Y Th
41. ts in this section flow directly from the science cases considered in the OCDD They are defined in the OCDD and are repeated here RSS NIR shall meet all science requirements listed below 4 1 1 Field Size The RSS NIR NIR will image the full 8 arcminute RSS VIS FOV across the linear dimension of the 2K x 2K Hawaii 2 RG chip from Rockwell Teledyne Given the fixed focal length of the visible NIR collimator this results in a reimaged plate scale of 76 0 microns arcsec The optical design must accommodate this field size for imaging and for spectroscopy The reimaged scale corresponds to 0 233 arcsec pixel or 4 2 pixels arcsec This plate scale is a compromise between the desire to have as large a longslit multi object space and imaging area as possible while simultaneously having a reasonable spatial spectral sampling of the smallest possible slit best seeing disc This Nyquist limited slit will be 0 5 with 2 pixels across 4 1 2 Wavelength Coverage The wavelength coverage agreed to at CoDR 0 90 1 4 um The actual wavelength coverage of the system will be 0 8 1 7 um based on the responsivity of the H2RG chip The Dewar will contain 3 low pass filters to limit this wavelength coverage in order to produce images and spectra that are limited in signal to noise ratio SNR by sky noise The wavelength range limited by the longest cut off filter will be defined as Hshort 4 1 3 Spatial Resolution RSS NIR will have slit widths of 0 5 to 1 25
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