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Toward the AO for the European ELT

Toward the AO for the European ELT. Norbert Hubin European Southern Observatory. http://www.eso.org/sci/facilities/develop/ao.html. Outlines. E-ELT Project: Telescope & instrument/AO roadmap Pathfinders supporting the ELTs Adaptive telescope progresses

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Toward the AO for the European ELT

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  1. Toward the AO for the European ELT Norbert Hubin European Southern Observatory http://www.eso.org/sci/facilities/develop/ao.html

  2. Outlines • E-ELT Project: Telescope & instrument/AO roadmap • Pathfinders supporting the ELTs • Adaptive telescope progresses • Single & Multi-Conjugate AO for MICADO • Single conjugate & Laser tomography for HARMONI • Single conjugate & Laser tomography for METIS • Conclusions

  3. The E-ELT Project The Telescope • 40-m class telescopeoptical-infraredtelescope • Segmentedprimarymirror • Adaptive Opticsassistedtelescope • Multi-LGSssidelaunched • Diffraction limited performance: • 12mas@K-band • Wide field of view: 10 arcmin • Mid-latitude site (Amazones/Chile) • Fastinstrument changes • VLT level of operationsefficiency.

  4. The E-ELT ProjectAdaptive telescope

  5. Adaptive 2.5 m M4 unit for 39 m 4974contactless actuators in optical area Max 160 µm stroke 31.5 mm pitch, triangular pattern 2480/2387 mm diameter Segmented Zerodur 1.95mm thin shell (6 petals) Backplate in Zerodur/SiC TBC Removable Actuator Brick design (198 bricks) On board M4 electronics Remote M4 Control System Flex joint hexapods for M4 Positioning System Large bearing + cable wrap for Nasmyth selector Mass: 10 tons Power: 8.4 kW

  6. The E-ELT Project Instrument Roadmap

  7. The E-ELT Project Instrument Roadmap • 1st Light Instruments SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO LTAO: Laser-Tomographic AO MOAO: Multi-Object AO XAO: Extreme-AO

  8. The E-ELT Project Instrument Roadmap • 2nd Pool Instruments SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO LTAO: Laser-Tomographic AO MOAO: Multi-Object AO XAO: Extreme-AO

  9. The E-ELT Project Instrument Roadmap • XAO Instrument SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO LTAO: Laser-Tomographic AO MOAO: Multi-Object AO XAO: Extreme-AO

  10. The E-ELT Project Instrument Roadmap • Various AO Flavors SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO LTAO: Laser-Tomographic AO MOAO: Multi-Object AO XAO: Extreme-AO

  11. Global vision & walking before running • All AO systems for E-ELT are challenging & costly: • Many new concepts are still in demonstration phase or have not been fully operated on smaller telescopes for science Pathfinders • Technologies required are often one step behind Dev. needed • Operation, Control & calibration strategies are still being figured out crucial effective operation of AO system for science Pathfinders • Global vision is essential to reduce cost & risks for all • 1 observatory cannot cope with all challenges alone Fair collaboration is highly desirable: TMT-GMT-ESO-LBT-Gemini-Keck-WHT-SUBARU... • Reasonableglobal pathfinding vision, good view of essential technological bricks & cross fertilization of ideas between teams is vital • Adaptive telescope: MMT- LBT- Magellan -VLT- E-ELT… • MCAO: MAD- Solar MCAO- Gems • GLAO-LTAO: MMT, SAM, MAD, AOF, CANARY • MOAO: Village, CANARY, RAVEN EAGLE • XAO- High contrast: Gemini, VLT, SUBARU, LBT? EPICS • Lasers, DMs, RTC, WFS detectors, smart algorithms, vibration control, operation… Philosophical slide SORRY

  12. AOF pathfinder • Single project structure covering all phases  Now in Testing GRAAL GALACSI DSM ASSIST 4LGSF • UT4 Upgrade • NGC • SPARTA ( Important R&D component embedded in AOF Project AO4ELT - Firenze

  13. ESO AOF: Pathfinding Role for EELT • “Soft” benefits: • Hands-on experience with an adaptive telescope • New AO modes: GLAO, LTAO & of course SCAO • Tight error budgets, high Strehl(GALACSI NFM, ERIS) • Calibration strategy, including on-sky, synthetic • Real Time Computer: AOF SPARTA brought us high up on learning curve • How to operate an adaptive telescope efficiently • Concrete Benefits: • EELT M4 is directly inspired from the DSM • SAGEM benefits from the synergy of thin shells (DSM, proto M4, M4 monolithic) • The Laser developed and funded by AOF is “as is” usable by EELT • The Launch telescope developed by AOF is “as is” usable by EELT • ESO has delivered a < 1e- RON detector @ 1.35 kHz !!! (with help from community: Ocam, FirstLight)

  14. Validate control strategy: AOF as 1st step • AOF control/operation strategy good starting point for end-to-end control strategy of ELT • SCAO • GLAO • LTAO • ELT more complex though • Segmented M1 • 5 mirror design to control • Less rigid structure • LGS operation more complex • Telescope metrology overlaps with AO metrologies • MCAO with one DM in telescope

  15. Validate end-to-end acquisition sequence (i.e AOF)

  16. Telescope AO Design & technology development

  17. Adaptive 2.5 m M4 unit for 39 m 4974contactless actuators in optical area Max 160 µm stroke 31.5 mm pitch, triangular pattern 2480/2387 mm diameter Segmented Zerodur 1.95mm thin shell (6 petals) Backplate in Zerodur/SiC TBC Removable Actuator Brick design (198 bricks) On board M4 electronics Remote M4 Control System Flex joint hexapods for M4 Positioning System Large bearing + cable wrap for Nasmyth selector Mass: 10 tons Power: 8.4 kW

  18. M4 Unit Preliminary Design Contract • Mirror technology optimization: • Development of new concepts for more reliable co-located sensors (more reliable electrical interface, easier installation) applicable to both glass and SiC M4 Unit solutions • New design of Brick interfaces to fulfill SiC manufacturing uncertainties • Demonstration prototype design on-going • Next steps: Demonstration prototype development & Completion of the Preliminary Design

  19. New Actuator bricks design The actual design of the brick is the one that will be tested on the updated demonstration prototype

  20. M4 Demonstration Prototype (DP) design The DP is representative of most critical aspects of the M4U: bricks, Reference body design, shell, actuator pattern, cophasing, actuator/capsens, cooling plant, local control system. 222 actuators 453.2 x 796 x 300mm

  21. Error budget estimate for M4 unit only

  22. 2.5 m M5 Tip-tilt Unit prototype LCS • Purpose • Verify architecture principles and ICD towards the contractors, provide worked example as reference to construction contract. • Verify our requirements and development standards • Amend requirements and development standards, if necessary • Provide environment to verify active damping strategies

  23. Instruments & Modules SCAO CAM MCAO SCAO IFU LTAO(GLAO) LTAO – not in cons. phase MIR SCAO

  24. From Single to Multi-Conjugate AO for MICADO • SCAO: Proposed as part of MICADO, a complementary AO capability for initial highest performance on compact targets. Also considered as risk mitigation & diffraction limited science before MAORY arrives (TBC) • Wavefront sensor (type depending on performance & dynamic range) • M4 adaptive mirror corrector (baseline fitting error 142 nm rms) ~50cm sampling on M1 • Additional telescope error budget to be taken into account. • MCAO: MAORY good, uniform performance over full field with high sky coverage. MAORY also proposes to include a SCAO mode for on-axis peak-Strehl performance. SCAO Sr(K) = 76% SCAO Sr(K) = 69% Courtesy: Le Louarn-ONERA No telescope WFE With telescope WFE (very preliminary 42 m)

  25. MAORY Strehl performance (0.8” seeing) • 6 LGSs side launched • 3 NGSs (IR WFSs) • 0.6 µm <  < 2.4 µm • S.R. >50% in K over 2’ • Central 1’ clear • DM conjugated at 4km, 12.7km • Two output ports • Sky coverage Galactic Pole • No telescope error budget included yet

  26. MAORY ensquared energy performance Performance to be updated for 39 m telescope Telescope error budget to be added

  27. MAORY for MICADO on-going work • Managerial: • Phase A study Nov 2007 – Dec 2009 • MCAO module approved by ESO as part of first-light instrumentation to serve E-ELT diffraction-limited camera MICADO; however awaiting from E-ELT funding • Project plan for next phases under consolidation • Negotiations between ESO and INAF (lead institute) are well advanced • INAF is supporting the project through its Directorate of Science • Current Consortium organization: INAF; Durham Univ; Obs. de Paris/LESIA; ESO

  28. MAORY related on-going work I • Consolidation of 20 W Raman fiber laser developed by ESO/TOPTICA • MAORY optical design trade-offs: alternative DM sizes, ADC, dichroic, LGS WFSs… • Sodium density profile measurements on-axis and in FoV (UBC collaboration • E2V Manufacturing of WFS detector: CMOS 840^2 pixels with 4eRON, 700Hz • Test controller development for the detector above: LAM & ESO GMT? • Smart algorithms for MCAO… reconstruction in collaboration with Linz team 1377 act. Piezo DM for SPHERE with its drive electronics

  29. MAORY related on-going work II • Laser spot truncation in SH WfSing see Poster Miska et al. • IR 320x256 eAPD array required for low WFSing in MAORY, LTAO, SCAO? • Medium size piezo-DM: addressing the recent DM manufacturing obsolescence problem in collaboration with TMT & CILAS • Alternative DM solutions: XINETICS, MZA, MG-ADS • Global collaborative effort to establish a RTC development plan & strategy for E-ELT AO instruments (U. Durham, LESIA, TNO, MPIA?, ESO)  goal coordinate RTC efforts with all E-ELT Consortia

  30. Sodium spot elongation truncation using full tomography information Triangle: Non Gaussian, 2x2 NGS, Diamond: 6x6 NGS Frim3D reconstr. Impact on LO or truth WFS, but truncation is ok fine on gaussian and non gaussian sodium profiles SEE MISKA et al. poster on that topic

  31. WFS detectors & controllers NIR SELEX detector GRAVITY 320x256 eAPD array RON<3e @ 1k frames/s; 47Kelvin Low order WFS for MAORY-LTAO But also RAPID @ LETI • E2V + LAM Potential detector for SCAO? • 240x240 pixels RON 0.2e @ 1.5kHz • E2V • 840x840 pixels; 24-μpixels • RON 3e @ 700 Hz frame/s • delivery Q4/2013-Q1/2014 1.6k x1.6k?

  32. Wavefront sensing CMOS detector

  33. Deformable mirror & RTC path finders RTC box CILAS 1370 actuators piezo DM with 4.5 mm pitch LGS tomography with 4 LGS WFSs 40x40 @ 1 kHz Co-processing cluster

  34. Single conjugate & Laser Tomography AO for HARMONI • SCAO: Proposed as part of HARMONI, a complementary AO capability for highest performance on “bright” targets: Solar system, High contrast science, GC… • Wavefront sensor (optimized for high contrast, differential tracking capability, …) • wavefront sensor: Visible or IR or both? • M4 adaptive mirror corrector (baseline fitting error 142 nm rms) ~50cm sampling on M1 • GLAO: Enhanced seeing capability using NGS wavefront sensors?: Earliest galaxies? • LTAO: High throughput, low emissivity, high sky coverage, “High” Sr performance required for faint targets: QSOs, GRBs, High-z G, etc… • 6 Laser Guide stars side launched 2’ diameter • 2 IR Natural Guide Star corrected with μDM • Uses M4 adaptive mirror (baseline fitting error 142 nm rms) • High throughput & low emissivity NGS 60” LGS 120” 4.2’

  35. Trade-offs on number / position of LGSs LTAO: 6LGS, 4 laser launch stations (LLS), TT stars close to center of FOV 500Hz, 500 iterations, 2 frames delay Seeing 0.8’’, L0=25m, tau0~3ms Importance of Cn2 profile assumptions for performance estimates M. Sarazin et al. 9 layers simulated, 9 layers reconstructed (unless otherwise noted)

  36. Single conjugate and Laser Tomography AO for HARMONI • Semi-analytic simulations for 39m telescope, LGSs @ 1’ (radius), 6LGSs • 40 atmospheric layers simulated, 7 reconstructed • PSF available for different wavelengths under request: 0.8, 1.0, 1.2, 1.6, 2.2, 10.0 um • On-axis PSF • With and without telescope WFE (very preliminary error budget) • Seeing=0.67 @ 30 degrees • Contain some “reasonable” TT jitter (±3mas rms); pessimistic (TBC)? telescope wind-skake & optimum control of low order modes critical Sr(K) =54% Sr(K) = 48.5 % With telescope WFE Without telescope WFE Courtesy: Le Louarn-ONERA

  37. LTAO performance (from Phase A 42 m) Without telescope error budget to be updated for 39 m

  38. Instrumentation arrangement optimization on E-ELT Nasmyth platform • Impact of telescope design change (4239m) • Design optomechnical implementation of telescope metrology, LTAO WFSing, and instrument pre-optics to ensure optimum configuration • Ensure good maintenance access on whole Nasmyth platform • Progress on end-to-end Wavefront control strategy to ensure completeness of metrology & AO sensor requirements • Major work on-going!

  39. On-going work for LTAO implementation at Nasmyth I

  40. Option 3 – Gravity invariant cryostatBig optics, but all static

  41. From SCAO to LTAO for METIS SCAO • Excellent on-axis • Integrated in METIS • Minimize residual jitter • ‘simple’ first light AO LTAO • Wide(r) field performance • Accepts fainter GS(s) • Increased sky coverage • LGS configuration trade-off on-going

  42. SCAO for METIS • SCAO internal to METIS • Cold, low (M)IR background • Dichroic first optic inside METIS • Cold! • Splits at ~2.5 micron • Full METIS field ~18x18” • Large field selector • Full METIS field • Allows or field de-rotation • ~40x40 sub-apertures • IR WFS • Embedded sources • Selex experience Gravity • Pyramid WFS • Detector available • But extended sources? Dichroic ELT Focus METIS Entrance Window Field Selector ADC? Pupil de-rotator

  43. LTAO Simulations LTAO Simulations 2.2 µm 3.7 µm 10 µm AO Only Best case scenario ESO Octopus Simulations/Miska Le Louarn AO + Telescope Only

  44. Next steps • Preliminary design of M4 unit • Consolidation of MAORY Project plan for next phases • Pursue technology development for MAORY • Optical design trade-off incl. 39 m update • Update Nasmyth platform configuration: telescope metrology- LTAO – HARMONI & METIS • Update performance estimates/error budgets for the different AO capabilities • Consolidate interfaces with instruments

  45. Conclusions • An aggressive AO program is being developed for the VLT • AO pathfinders for E-ELT are on-going @ VLT, WHT,… • Major efforts & collaborations to bring key technologies to appropriate TRL • Facilitating AO community effort to address remaining key AO fundamental issues (calibration, identification, control, tomography, LGS & NGS WFSing, simulation….) • Preparing for construction of E-ELT AO capabilities • Setting up Consortium for the AO instrumentation • The main power of the E-ELT will reside in achieving, with the help of AO, a spatial resolution never achieved at optical/infrared wavelength to this depth before.

  46. THANK YOU for your attention

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