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NGAO System Design Phase Update Peter Wizinowich, Rich Dekany, Don Gavel, Claire Max for NGAO Team SSC Meeting January 24, 2007 Presentation Sequence • SSC Co-Chair Questions • Management Update A. B. C. D. E. Management Structure Systems Engineering Management Plan Documentation & Coordination Instruments Working Group Project Report #1 • Technical Update – Science Requirements – Performance Budgets – Trade Studies • Summary 2 SSC Co-Chair Questions All of the following questions are addressed in the Systems Engineering Management Plan (summarized in the following Management update slides): 1. What is the product of this study phase? • Following Keck development process (see System Design phase deliverables on slide 6). Includes conceptual design (with options), initial cost estimate & management plan for remaining project. Instrument concepts developed to proposal level (precursor to their System Design phase). 2. Are any intermediate reviews planned? • Frequent internal product reviews, including cost reviews in Aug & Dec. SDR at end of this phase (3/31/08). Project reports provided prior to each SSC meeting. 3. Who is doing what, and what % of time is each person devoting to NGAO? • Details in project plan. High level summary of key personnel on slide 10. 4. What are the major goals/milestones of this phase? • See milestones on slide 9. 3 SSC Co-Chair Questions 5. What are the big issues and how are they being addressed? • • Big picture: Cost, schedule & performance + structuring the program to suit the funding. Science & engineering team working closely with management to produce a compelling & realistic vision. Near term: Science community input & team ramp-up. Engaging scientists in science case requirements & performance budgets. Freeing personnel from other responsibilities. 6. What is the timescale for this phase and when can the SSC expect a full report? • See schedule on slide 15. 7. What is the relationship between the NGAO team and the AOWG – – – – AOWG – Bouchez, Dekany, Koo, Larkin, Liu (co-chair), Macintosh, Marchis, Matthews, Max (co-chair) + Ellis (rotating on) The AOWG was a very active participant in the NGAO proposal. Max, Liu & Marchis are leading the science case requirements AOWG last met 8/06. 8. Comparison of NGAO versus planned AO performance of current generation. Why should we believe new models? – Addressed in the performance budgets section. 4 A. Management Structure • • Proposal approved at Jun/06 SSC & Board meetings WMKO, UCO & COO Directors subsequently established an Executive Committee (EC) to manage System Design phase: Wizinowich-WMKO (chair), Dekany-Caltech, Gavel-UCSC, MaxUCSC, CFAO (project scientist) 5 B. Systems Engineering Management Plan (SEMP) • SEMP submitted to Directors at end of Sept/06 – – • System design started Oct/06 – • Verbal approval received to proceed Budget approval being finalized Completion planned for mid-FY08 Products of this study phase (Q1) - System design phase deliverables – – – – System Requirements Document - Science & Observatory requirements & flow down to system requirements System Design Manual – Performance budgets, functional requirements, system & subsystem architectures SEMP – For remaining NGAO phases System Design Report – Summary for System Design Review 6 B. SEMP: Approach Science Requirements 1. 2. 3. 4. Initial Concept Performance Assessment Initial focus on requirements & performance budgets to ensure that we understand largest levers on the design Initial attempt at defining the AO system architecture & the functional requirements for the major systems In parallel with 1 & 2 perform trade studies to better understand the appropriate design choices A process of iteration and refinement will lead to the final version of the AO architecture & major systems requirements • 5. Technical Implications Includes continued development of performance budgets & functional requirements Develop cost estimates & plans for remainder of NGAO project 7 B. SEMP: Budget Cost ($k) WBS Name FY07 FY08 Total 1 Management 74 49 123 2 System Requirements 119 3 122 3 System Design 560 90 650 4 Systems Engineering Management Plan 5 79 84 Travel/Procurements 40 20 60 Contingency (part of overall Observatory contingency) 10 94 104 808 335 1143 Total ($k) = Work (hours) Institute FY07 FY08 Total COO 2836 702 3589 UCSC 2991 845 3926 WMKO 5355 1852 7360 Students 1850 0 1850 Total = 13032 3399 16725 $163k increase in cost of labor since proposal, due to distributed project nature Total work same as in original proposal 8 B. SEMP: Milestones MILESTONE DATE DESCRIPTION SD SEMP Approved 10/9/06 Approval of plan by Directors SD phase contracts in place 10/27/06 Contracts issued to Caltech & UCSC for the system design phase Science Requirements Summary v1.0 10/27/06 Initial Release of Science Requirements as input to trade studies & performance budgeting System Requirements Document v1.0 12/8/06 Initial release with emphasis on the science requirements Performance Budgets Summary v1.0 2/27/07 1st round of all performance budgets complete & documented System Requirements Doc v2.0 3/22/07 2nd release Trade Studies Complete 5/25/07 All trade studies complete & documented (as a series of KAONs) System Requirements Doc v3.0 7/12/07 3rd release of System Requirements System Design Manual v1.0 8/31/07 1st release of System Design Manual Technical Risk Analysis v1.0 11/13/07 1st round of project risk analysis complete & documented Cost Review Complete 11/30/07 Project cost estimates complete, documented & internally reviewed System Design Manual v2.0 1/8/07 2nd release System Design Review Package Distributed 3/4/08 SDR documents sent to reviewers System Design Review 3/31/08 SDR meeting SDR Report & Project Planning Presentation at SSC meeting 4/14/08 Final SD phase report including 9 results of SDR & project plans B. SEMP: Team Name Institute % NGAO-relevant Expertise Bouchez COO 11 AO systems & science Dekany COO 33 EC; AO systems & mgmt Moore COO 31 Instruments Velur COO 38 Lasers & wavefront sensors (mechanical) Bauman UCSC 21 Optics Gavel UCSC 33 EC; AO systems & mgmt Max UCSC 22 EC Science Team chair Postdoc UCSC 46 AO science Adkins WMKO 15 Instruments & Project Mgmt Chin WMKO 18 Electronics Flicker WMKO 38 AO Modeling Johansson WMKO 18 AO Control (software & electronics) Le Mignant WMKO 15 AO science operations Meguro WMKO 13 Mechanical Neyman WMKO 67 AO systems Wizinowich WMKO 36 EC chair; AO systems & mgmt Represents 84% of the work force. 10 C. Documentation & Coordination • • NGAO Twiki site at http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/WebHome Includes collections for – Team meetings • – Executive committee • • – Table of WBS elements, planning sheets & products Performance budgets • – Planning & tracking documents EC weekly meeting minutes Work packages • – Agendas & documents posted in advance; action items posted & followed up Meeting summaries & products Science team 11 D. Instruments Working Group • Instruments Working Group (IWG) being formed for NGAO System Design Phase – Focused on instrumentation related matters • Instrument specialist perspective for NGAO • Resource for AO system design team on instrumentation issues – Organization (6 to 8 members) • 3 to 4 funded from current NGAO plan – – – – Responsible for most of technical work related to NGAO instrumentation WBS Sean Adkins (IWG chair, overall systems, detectors, electronics & interfaces) Anna Moore (instrument generalist, optical & mechanical) James Larkin/UCLA IR Lab staff members (instrument design, optical & mechanical, cryogenics experience) – TBD software engineer • 3 to 4 TBD volunteers from NGAO science team – Primary contacts with science team for instrument related science requirements • Regular meetings will be held involving the entire group • Additional assistance & advice will be sought from the diverse base of the collective instrumentation & technical resources at UC & CIT 12 E. Project Report #1 • • Directors’ requested written project reports prior to each SSC meeting 1st report submitted to Directors on Jan. 19 http://www.oir.caltech.edu/twiki_oir/bin/view.cgi/Keck/NGAO/SystemDesignPhasePlanning • • • Good progress made on initiating NGAO System Design phase & on building up an effective team Emphasis to date, as planned, on understanding the major design drivers through a process of iteratively developing the science case requirements & the performance budgets Work has begun on a number of trade studies in support of the performance budgets & the future design choices 13 E. Project Report #1 # MILESTONE DATE DESCRIPTION 1 SD SEMP Approved 10/9/06 2 SD phase contracts in place 10/27/06 Contracts issued to Caltech & UCSC for the system design phase. $50k initial contracts issued on 12/20 3 Science Case Requirements Summary v1.0 Release 10/27/06 Initial Release as input to trade studies & performance budgeting V1.0 to be completed in Jan/07 4 System Requirements Document v1.0 Release 12/8/06 Initial release of System Requirements with emphasis on science requirements 5 Performance Budgets Summary v1.0 Release 2/27/07 1st round of all performance budgets complete & documented Good progress 6 System Requirements Doc v2.0 Release 3/22/07 2nd release of System Requirements Document Not started yet 7 Trade Studies Complete 5/25/07 All trade studies complete (Keck Adaptive Optics Notes) Good progress Approval of this plan by the Directors. SEMP released to Directors on 9/29/06. STATUS Verbal approval received. Written approval requested V1.0 to be completed in Jan/07 14 E. Project Report #1 15 E. Project Report #1 Budget • • $772k budgeted for FY07 in 5-year plan $110k spent in 1st quarter – – Low due to slower than planned ramp up of personnel Average of 4.3 FTEs Summary • Good technical progress as you will see in the following slides • Team and management processes now largely in place • Expect the teams rate of progress to be close to the rate in the plan during the 2nd quarter 16 Science Case Requirements & System Requirements Max, Ghez, Law, Liu, Lu, Macintosh, Marchis, Steidel Neyman, Wizinowich Science Requirements Process • Approach: – Start from significant science case development in proposal – Analyze limited set of these key science cases in order to understand and document the requirements on NGAO + Instruments – Begin with cases that stress AO design the most in multiple directions – Progress to include more science cases – Iterate 4 times with AO & instrument requirements • For each case, discuss – Science goals, proposed observations, AO performance requirements, instrument requirements 19 Science Requirements & Performance Budget Process 20 Science Case Requirements Document Release 1 Contents • JWST and ALMA capabilities • Future AO capabilities of other observatories • Key science cases and what they stress most: – Multiplicity, size, shape of minor planets • High contrast, wavefront error, visible light performance – Planetary & brown dwarf companions to low mass stars • High contrast – General relativistic effects in the Galactic Center • Astrometry and radial velocity accuracy – Assembly and star formation history of high z galaxies • Lower backgrounds, multiple deployable IFUs, sky coverage 21 JWST capabilities • • • Cryogenic 6.5-m space telescope, launch in 2013 Higher faint-source sensitivity than Keck NGAO, due to low backgrounds Not diffraction limited below K band – – • Primary mirror spec NIRCAM px scale 0.035”, NIRSpec px scale 0.1” Areas where Keck NGAO would complement JWST 1. Spectroscopy @ spatial resolution better than 0.1”, = 0.6 - 2 μm 2. Imaging @ spatial resolution better than 0.07”, = 0.6 - 2 μm 3. Multi-IFU spectroscopy 22 Key science requirements: Multiplicity, size, shape of minor planets • Minor planet formation history and interiors by accurate measurements of size, shape, companions • Small, on-axis imaging field ( ≤ 3 arc sec) • Relative photometry to 5%, astrometry ≤ 5 mas, wavefront error ≤ 170 nm, contrast H 5.5 at 0.5 arc sec • Instruments: – Imaging: visible and near-IR – Near IR IFU spectroscopy: 1.5 arc sec field; still need to specify spectral resolution • Observing modes: non-sidereal tracking, <10 minute overhead switching between targets, consider queue or flexible scheduling Asteroid Sylvia and moons 23 Key Science Requirements: Planetary & brown dwarf companions to low mass stars • Faintness of low-mass stars, brown dwarfs, and the youngest stars make them excellent NGAO targets • Small imaging field ≤ 5 arc sec • Relative photometry to 5%, astrometry to PSF FWHM/10, contrast H = 13 at 1 arc sec • Instruments: – Imaging 0.9 - 2.4 microns – Single near IR IFU spectroscopy, still need to specify spectral resolution • Observing modes: coronagraph needed 24 Key Science Requirements: General relativistic effects in the Galactic Center • Measure General Relativistic prograde precession of stellar orbits in Galactic Center • Requires astrometric precision of 100 as (now 250 as) and radial velocity precision to 10 km/sec (now 20 km/sec) • K band, wavefront error ≤ 170 nm • Imaging field 10 x 10 arc sec • Near IR IFU spectra, R ≥ 4000, FOV ≥ 1” x 1”, need IR ADC Need to evaluate optimal spectral resolution 25 Key Science Requirements: Assembly and star formation history of high z galaxies • Redshifts 1.5 ≤ z ≤ 2.5: most active star formation, form bulges & disks – Optical lines such as H are shifted into near IR • Density 2 - 20 / sq arc sec 6 to 12 IFUs in field of regard • J, H, K bands • IFU fields ~ 1 x 3 arc sec for sky subtraction, 50 mas spaxels, R = 3000 - 4000, EE > 50% within 50 mas for optimal tip-tilt stars • Low backgrounds: AO system Need to evaluate which high-z < 10-20% of (sky + telescope) science could be done with higher backgrounds 26 Science requirements summary to date • Wavefront error 170 nm or better – Need sensitivity study to see how science would fare if wavefront error were 200 nm • Relative photometry to 5% • Contrast H 5.5 at 0.5 arc sec, H 13 at 1 arc sec • Astrometry: companions to 5 mas, Galactic Center to 100 as. Need near-IR ADC. • K-band backgrounds: AO system + IFU < 10-20% of (sky + telescope) – Need sensitivity study to see how high-z science would fare at higher background levels • Not yet found a compelling science case for a large contiguous field (i.e., MCAO) 27 Instruments & observing mode requirements, to date • Instruments: – Refining the requirements developed for the proposal – On-axis near-IR imager, field ~ 10 x 10 arc sec, coronagraph – On-axis visible imager (to 0.6 or 0.7 m), field ~ 3 x 3 arc sec, coronagraph? – Near IR deployable IFU: • • • • 6 - 12 channels, field of regard TBD Field of view ~ 1 x 3 arc sec 50 mas spaxels, EE > 50% within 50 mas for optimal tip-tilt stars Still need to evaluate optimum spectral resolution • Observing modes: – Non-sidereal tracking, <10 minute overhead switching between targets, consider queue or flexible scheduling 28 NGAO Performance Budget Development Dekany, Ghez, Marchis, Max, Liu, Gavel, Flicker, Wizinowich, Cameron, Lu, Britton, Macintosh, Neyman, Ireland, Olsen, Bouchez, Law, Bauman, Le Mignant, Johansson, Chin Developing Science-based Performance Budgets • Systems engineering will consider all of the following budgets – – – – – – – – – – Model assumptions Model/tool validation Wavefront error vs. sky coverage for 5-7 science cases Photometric precision in crowded and sparse stellar fields Astrometric accuracy at the GC and in sparse fields High-contrast for diffuse debris disks and compact companions Polarimetric precision for high-contrast observations Transmission/background/SNR for several science cases Observing efficiency Observing uptime 30 Performance Budget Development Goals • Produce a technical report – Describing the major drivers, including experimentally supportive information, quantitative background, and potential simulation results • Produce a numerical engineering tool to support future design iterations – Emphasizing abstracted quantitative scaling laws and interdependencies • Support science requirements development – Capturing the experience of the science team and reflecting quantitative underpinning to current limitations 31 Wavefront Error and Encircled Energy • Science Cases – Maintain all cases from the June ‘06 NGAO proposal • Key Drivers for initial budget – Uncertainty in tomographic reconstruction error – Uncertainty in sodium laser photoreturn from the mesosphere • Per delivered Watt, as a function of different pulse formats • Requires 50W class lasers to investigate non-linear optical pumping effects – Uncertainty in multi-NGS tilt tomography efficacy • Not included in original budget development – Uncertainty in tip/tilt control efficacy with large tip/tilt mirrors 32 Wavefront error budgets Keck Wavefront Error Budget Summary Band (microns) V R I J H K m 0.55 0.70 0.91 1.25 1.65 2.20 m 16% 31% 17% 30% 24% 22% /D (mas) 11.3 14.4 18.8 25.8 34.0 45.4 • For observations of – – – – – – TNO multiplicity Galactic Center Field galaxies Io Nearby AGN Gravitational Lenses Wavefront Error (rms) High-order Errors (LGS Mode) Atmospheric Fitting Error Bandwidth Error High-order Measurement Error LGS Tomography Error Asterism Deformation Error Multispectral Error Scintillation Error WFS Scintillation Error 55 50 58 60 22 25 15 10 nm nm nm nm nm nm nm nm 44 74 150 5 0.50 30 0.37 Alloc 43 15 20 10 0 1 16 13 18 4 20 25 15 nm nm nm nm nm nm nm nm nm nm nm nm nm 64 Dekens Ph.D Alloc Alloc Alloc 30 4.0 from TMT 44 10 Alloc Alloc Alloc Strehl Ratios Subaps Hz W beacon(s) m LLT zenith angle, H band Scint index, H-band 0.67 0.72 0.64 0.62 0.94 1.00 0.97 0.99 0.78 0.81 0.76 0.75 0.96 1.00 0.98 0.99 0.87 0.89 0.85 0.84 0.98 1.00 0.99 1.00 0.93 0.94 0.92 0.91 0.99 1.00 0.99 1.00 0.96 0.96 0.95 0.95 0.99 1.00 1.00 1.00 0.98 0.98 0.97 0.97 1.00 1.00 1.00 1.00 Acts 0.79 0.97 0.95 0.99 1.00 1.00 1.00 0.98 0.96 1.00 0.95 0.92 0.97 0.86 0.98 0.97 0.99 1.00 1.00 1.00 0.99 0.97 1.00 0.97 0.95 0.98 0.92 0.99 0.98 1.00 1.00 1.00 1.00 0.99 0.98 1.00 0.98 0.97 0.99 0.95 0.99 0.99 1.00 1.00 1.00 1.00 1.00 0.99 1.00 0.99 0.98 0.99 0.97 1.00 0.99 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.99 0.99 1.00 0.99 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.99 1.00 1.00 1.00 1.00 1.00 1.00 1.00 118 nm Uncorrectable Static Telescope Aberrations Uncorrectable Dynamic Telescope Aberrations Static WFS Zero-point Calibration Error Dynamic WFS Zero-point Calibration Error Go-to Control Errors Residual Na Layer Focus Change DM Finite Stroke Error DM Hysteresis High-Order Aliasing Error DM Drive Digitization Uncorrectable AO System Aberrations Uncorrectable Instrument Aberrations DM-to-lenslet Misregistration (all sources) m/s Na layer vel um P-P stroke Subaps bits 68 nm Angular Anisoplanatism Error 0 nm Total High Order Wavefront Error • During requirements flowdown & initial design, all performance budgets will be used for rapid reevaluation of performance cost/benefit Parameter Angular Error (rms) Tip/Tilt Errors Tilt Measurement Error (one-axis): Tilt Bandwidth Error (one-axis) Tilt Anisoplanatism Error (one-axis) Residual Centroid Anisoplanatism Residual Atmospheric Dispersion Science Instrument Mechanical Drift Long Exposure Field Rotation Errors Residual Telescope Pointing Jitter (one-axis) 5.18 0.63 5.99 1.99 1.06 0.50 0.50 4.85 Total Tip/Tilt Error (one-axis) mas mas mas mas mas mas mas mas 9.61 mas Total Effective Wavefront Error Sky Coverage Galactic Lat. 0 arcsec 136 nm High Order Strehl 0.10 0.24 0.43 0.64 0.77 0.86 Parameter Strehl ratios Equivalent WFE (rms) 63 8 73 24 13 6 6 59 nm nm nm nm nm nm nm nm 17.8 61.0 40.2 5 20 Alloc Alloc 29 mag (mV) Hz arcsec x reduction x reduction (0.2 mas) (0.2 mas) Hz input disturbance 0.49 0.98 0.42 0.87 0.39 0.99 0.99 0.53 0.61 0.99 0.54 0.91 0.44 1.00 1.00 0.64 0.73 0.99 0.67 0.95 0.84 1.00 1.00 0.75 0.83 1.00 0.79 0.97 0.96 1.00 1.00 0.85 0.90 1.00 0.87 0.98 1.00 1.00 1.00 0.91 0.94 1.00 0.92 0.99 1.00 1.00 1.00 0.95 116 nm Tip/Tilt Strehl 0.22 0.31 0.44 0.59 0.72 0.82 179 nm Total Strehl 0.02 0.08 0.19 0.38 0.55 0.71 30 deg Corresponding Sky Coverage 5.0% This fraction of sky can be corrected to the Total Effective WFE shown Assumptions / Parameters r0 Theta0_eff Sodium Abund. Science Target: LOWFS Star(s): 0.165 m at this zenith 1.98 arcsec at this zenith 4 x 109 atoms/cm2 SCAO MOAO 2 TT star(s) & Wind Speed Outer Scale LGS Ast. Rad. 13.67 m/s 75 m 0.08 arcmin 0 TTFA star(s) Zenith Angle HO WFS Rate HO WFS Noise HOWFS anti-aliasing LO WFS rate LO WFS Noise 30 1114 1.7 NO 915 4.5 deg Hz e- rms Hz e- rms SH using CCD SH using SNAP Example for LGS observation of TNO using two galactic M-dwarfs as tip/tilt stars 33 Improving Performance Predictions • Performance versus Blue Book – Delivered system & science instrument didn’t achieve some requirements – Environment different than some assumptions • Why will NGAO performance estimates be better – Experience at Palomar, Lick & Keck – Better understanding of Keck environment – Performance estimation tools more complete & anchored to actual performance • For effects such as multi-guide star tomography for which we don’t have real-world experience: – Based on modeling and detailed simulations • Comparing & validating these tools (TMT, Gemini, COO, Keck, UCO) – Aided by lab experiments (e.g. LAO) – Undoubtedly there will be “real-world” effects that we are not yet taking into account 34 Keck LGS AO Wavefront Error Budget LGS (10th mag) Explanations Blue Book Measured NGAO tool Atmospheric fitting 123 128 102 Telescope fitting 105 60 70 Camera 35 113 113 NIRC2 aberrations DM bandwidth 36 157 143 Lower bandwidth DM measurement 98 142 135 Lower laser power TT bandwidth 34 109 30 Vibrations - will be added to NGAO tool TT measurement 34 23 4 LGS focus error 35 36 25 Focal anisoplanatism 127 175 151 Different atmosphere LGS high-order error 0 80 80 Centroid anisoplanatism 0 0 21 Atmospheric dispersion 0 0 81 Miscellaneous 0 0 0 Dyn calibs, tel, poorly sensed, atmos disp Miscellaneous (NGAO) 0 0 53 Seven ~20 nm terms Calibrations 30 0 40 Total wavefront error 243 358 330 K-band Strehl 0.62 0.35 0.41 Percentile Seeing 50% 75% 65% 35 NGAO Trade Studies Dekany To date: Bauman, Clare, Gavel, Flicker, Kellner, Neyman, Velur Design Trade Studies • Trade studies were initiated at the start of System Design phase • We have completed or nearly completed: – – – – – – Methods of mitigating laser Rayleigh backscatter Laser guide star asterism & geometry Multi-Object (MOAO) & Multi-Conjugate (MCAO) architectures Variable vs fixed laser asterism on the sky Fast tip/tilt opto-mechanical implementation options Low order wavefront sensor type & number • Additional design studies now underway include: – – – – – LGS wavefront sensor architecture & type Science instrument re-use Telescope static & dynamic errors Interferometer support Sodium return versus laser format 37 Mitigating Laser Rayleigh Backscatter • Evaluate impact of unwanted Rayleigh backscatter on NGAO system performance • Status: – Evaluated the intensity of the Rayleigh as well as aerosol and cirrus backscatter as seen at the Keck focal plane – Surveyed the available lasers and pulse formats – Surveyed methods of blocking Rayleigh – Interim results at NGAO meeting 3 (12/13/06) • Best rejection choice: appropriately pulsed laser which can have a gated return so that almost no Rayleigh background is encountered • However, most powerful & promising lasers in terms of sodium return per Watt, are CW 38 LGS Asterism & Geometry • Find the simplest LGS asterism geometry meeting the performance budget goals – Number of guidestars – Constellation configuration – Constellation size • Conclusions – Simulations of tomography generally validate the theoretical scaling laws – 5 LGS constellation works ok on 20 arcsec field – 7-9 LGS will be needed on 90 arcsec field • KAON 429 39 Multi-Object vs Multi-Conjugate AO • Understand potential risks, technical challenges, limitations, advantages & room for improvement with Multi-Object (MOAO) & Multi-Conjugate (MCAO) MCAO Laser Beams Laser Beams MOAO Hybrid Laser Beams LGS Wavefront Sensors Dichroic Tomography Computer Dichroic Science Instruments LGS Wavefront Sensors • • Dichroic Deformable Mirrors Tomography Computer DM Science Detector DM Science Instruments Science Detector LGS Wavefront Sensors Deformable Mirrors Tomography Computer Calculated performance for 1, 2 & 3 DM MCAO systems & compared to small sub-field IFU or imager arms, each with a DM Conclusions: – MCAO offers a contiguous field for imaging, but a large error term. “Generalized anisoplanatism” dominates in wide-field cases – MOAO greatly reduces anisoplanatic error at cost of non-contiguous field • KAON 452 40 Summary • Management update: – Systems Engineering Management Plan in place – Executive Committee working well together – Ramp up slower than planned, but team & processes now in place – Good technical progress is being made • Technical update: – Iterations between science requirements & performance budgets are achieving our goals of understanding what is really needed – Learning what we need to from architecture trade studies – Building base for design choices & cost/benefit trades We now have the management structure, plan & enthusiastic team to produce an excellent NGAO System Design. 41