Toward the AO for the European ELT Norbert
Toward the AO for the European ELT Norbert Hubin European Southern Observatory http: //www. eso. org/sci/facilities/develop/ao. html
Outlines n E-ELT Project: Telescope & instrument/AO roadmap n Pathfinders supporting the ELTs n Adaptive telescope progresses n Single & Multi-Conjugate AO for MICADO n Single conjugate & Laser tomography for HARMONI n Single conjugate & Laser tomography for METIS n Conclusions
The E-ELT Project The Telescope • 40 -m class telescope opticalinfrared telescope • Segmented primary mirror • Adaptive Optics assisted telescope • Multi-LGSs side launched • Diffraction limited performance: 12 mas@K-band Wide field of view: 10 arcmin • Mid-latitude site (Amazones/Chile) • Fast instrument changes • VLT level of operations efficiency.
The E-ELT Project Adaptive telescope 4
Adaptive 2. 5 m M 4 unit for 39 m 4974 contactless actuators in optical area Max 160 µm stroke 31. 5 mm pitch, triangular pattern 2480/2387 mm diameter Segmented Zerodur 1. 95 mm thin shell (6 petals) Backplate in Zerodur/Si. C TBC Removable Actuator Brick design (198 bricks) On board M 4 electronics Remote M 4 Control System Flex joint hexapods for M 4 Positioning System Large bearing + cable wrap for Nasmyth selector Mass: 10 tons Power: 8. 4 k. W
The E-ELT Project Instrument Roadmap Instruments - First Light AO Mode λ (µm) Resolution Fo. V / Sampling Add. Mode E-CAM – 2023 SCAO, MCAO - IMG - MRS 0. 8 – 2. 4 BB, NB 3000 53. 0” / 3 mas Astrometry 40 mas Coronography E-IFU – 2023 SCAO, LTAO - IFU 0. 5 – 2. 4 4000 10 000 20 000 0. 5× 1. 0” / 4 mas 5. 0× 10. 0” / 40 mas Coronography E-MIDIR – 2024/2028 SCAO, LTAO - IMG - MRS - IFU 3 – 13 3 - 13 3 -5 BB, NB 5000 100 000 18” / 12 mas Coronography Polarimetry E-HIRES - 2024/2028 SCAO - HRS 0. 37 – 0. 71 0. 84 – 2. 50 200 000 120 000 0. 82” 0. 027”× 0. 5” Polarimetry MOAO Slits IFUs 0. 37 – 1. 4 0. 8 – 2. 45 300 - 2500 5000 – 30 000 4000 – 10 000 6. 8” / 0. 1” 420’ / 0. 3” 2” / 40 mas Multiplex ~ 400 Multiplex ~10 Imaging? EPOL IFS 0. 6 – 0. 95 – 1. 65 125 – 20 000 2. 0” / 2. 3 mas 0. 8“ / 1. 5 mas Coronography Polarimetry E-MOS - 2024/2028 E-PCS - 2027/2030 XAO 0. 4”× 1. 5” / 4 mas
The E-ELT Project Instrument Roadmap • 1 st Light Instruments - First Light AO Mode λ (µm) Resolution Fo. V / Sampling Add. Mode E-CAM – 2023 SCAO, MCAO - IMG - MRS 0. 8 – 2. 4 BB, NB 3000 53. 0” / 3 mas Astrometry 40 mas Coronography E-IFU – 2023 SCAO, LTAO - IFU 0. 5 – 2. 4 4000 10 000 20 000 0. 5× 1. 0” / 4 mas 5. 0× 10. 0” / 40 mas Coronography E-MIDIR – 2024/2028 SCAO, LTAO - IMG - MRS - IFU 3 – 13 3 - 13 3 -5 BB, NB 5000 100 000 18” / 12 mas Coronography Polarimetry E-HIRES - 2024/2028 SCAO - HRS 0. 37 – 0. 71 0. 84 – 2. 50 200 000 120 000 0. 82” 0. 027”× 0. 5” Polarimetry MOAO Slits IFUs 0. 37 – 1. 4 0. 8 – 2. 45 300 - 2500 5000 – 30 000 4000 – 10 000 6. 8” / 0. 1” 420’ / 0. 3” 2” / 40 mas Multiplex ~ 400 Multiplex ~10 Imaging? EPOL IFS 0. 6 – 0. 95 – 1. 65 125 – 20 000 2. 0” / 2. 3 mas 0. 8“ / 1. 5 mas Coronography Polarimetry E-MOS - 2024/2028 E-PCS - 2027/2030 XAO SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO MOAO: Multi-Object AO XAO: Extreme-AO 0. 4”× 1. 5” / 4 mas LTAO: Laser-Tomographic AO
The E-ELT Project Instrument Roadmap • 2 nd Pool Instruments - First Light AO Mode λ (µm) Resolution Fo. V / Sampling Add. Mode E-CAM – 2023 SCAO, MCAO - IMG - MRS 0. 8 – 2. 4 BB, NB 3000 53. 0” / 3 mas Astrometry 40 mas Coronography E-IFU – 2023 SCAO, LTAO - IFU 0. 5 – 2. 4 4000 10 000 20 000 0. 5× 1. 0” / 4 mas 5. 0× 10. 0” / 40 mas Coronography E-MIDIR – 2024/2028 SCAO, LTAO - IMG - MRS - IFU 3 – 13 3 - 13 3 -5 BB, NB 5000 100 000 18” / 12 mas Coronography Polarimetry E-HIRES - 2024/2028 SCAO - HRS 0. 37 – 0. 71 0. 84 – 2. 50 200 000 120 000 0. 82” 0. 027”× 0. 5” Polarimetry MOAO Slits IFUs 0. 37 – 1. 4 0. 8 – 2. 45 300 - 2500 5000 – 30 000 4000 – 10 000 6. 8” / 0. 1” 420’ / 0. 3” 2” / 40 mas Multiplex ~ 400 Multiplex ~10 Imaging? EPOL IFS 0. 6 – 0. 95 – 1. 65 125 – 20 000 2. 0” / 2. 3 mas 0. 8“ / 1. 5 mas Coronography Polarimetry E-MOS - 2024/2028 E-PCS - 2027/2030 XAO SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO MOAO: Multi-Object AO XAO: Extreme-AO 0. 4”× 1. 5” / 4 mas LTAO: Laser-Tomographic AO
The E-ELT Project Instrument Roadmap • XAO Instruments - First Light AO Mode λ (µm) Resolution Fo. V / Sampling Add. Mode E-CAM – 2023 SCAO, MCAO - IMG - MRS 0. 8 – 2. 4 BB, NB 3000 53. 0” / 3 mas Astrometry 40 mas Coronography E-IFU – 2023 SCAO, LTAO - IFU 0. 5 – 2. 4 4000 10 000 20 000 0. 5× 1. 0” / 4 mas 5. 0× 10. 0” / 40 mas Coronography E-MIDIR – 2024/2028 SCAO, LTAO - IMG - MRS - IFU 3 – 13 3 - 13 3 -5 BB, NB 5000 100 000 18” / 12 mas Coronography Polarimetry E-HIRES - 2024/2028 SCAO - HRS 0. 37 – 0. 71 0. 84 – 2. 50 200 000 120 000 0. 82” 0. 027”× 0. 5” Polarimetry MOAO Slits IFUs 0. 37 – 1. 4 0. 8 – 2. 45 300 - 2500 5000 – 30 000 4000 – 10 000 6. 8” / 0. 1” 420’ / 0. 3” 2” / 40 mas Multiplex ~ 400 Multiplex ~10 Imaging? EPOL IFS 0. 6 – 0. 95 – 1. 65 125 – 20 000 2. 0” / 2. 3 mas 0. 8“ / 1. 5 mas Coronography Polarimetry E-MOS - 2024/2028 E-PCS - 2027/2030 XAO SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO MOAO: Multi-Object AO XAO: Extreme-AO 0. 4”× 1. 5” / 4 mas LTAO: Laser-Tomographic AO
The E-ELT Project Instrument Roadmap • Various AO Flavors Instruments - First Light AO Mode λ (µm) Resolution Fo. V / Sampling Add. Mode E-CAM – 2023 SCAO, MCAO - IMG - MRS 0. 8 – 2. 4 BB, NB 3000 53. 0” / 3 mas Astrometry 40 mas Coronography E-IFU – 2023 SCAO, LTAO - IFU 0. 5 – 2. 4 4000 10 000 20 000 0. 5× 1. 0” / 4 mas 5. 0× 10. 0” / 40 mas Coronography E-MIDIR – 2024/2028 SCAO, LTAO - IMG - MRS - IFU 3 – 13 3 - 13 3 -5 BB, NB 5000 100 000 18” / 12 mas Coronography Polarimetry E-HIRES - 2024/2028 SCAO - HRS 0. 37 – 0. 71 0. 84 – 2. 50 200 000 120 000 0. 82” 0. 027”× 0. 5” Polarimetry MOAO Slits IFUs 0. 37 – 1. 4 0. 8 – 2. 45 300 - 2500 5000 – 30 000 4000 – 10 000 6. 8” / 0. 1” 420’ / 0. 3” 2” / 40 mas Multiplex ~ 400 Multiplex ~10 Imaging? EPOL IFS 0. 6 – 0. 95 – 1. 65 125 – 20 000 2. 0” / 2. 3 mas 0. 8“ / 1. 5 mas Coronography Polarimetry E-MOS - 2024/2028 E-PCS - 2027/2030 XAO SCAO: single-conjugated AO MCAO: Multi-Conjugated-AO MOAO: Multi-Object AO XAO: Extreme-AO 0. 4”× 1. 5” / 4 mas LTAO: Laser-Tomographic AO
Global vision & walking before running n All AO systems for E-ELT are challenging & costly: n Ø Many new concepts are still in demonstration phase or have not been fully operated on smaller telescopes for science Pathfinders e Ø Technologies required are often one step behind Dev. needed d i l s are still being figured out l Ø Operation, Control & calibration strategies a c crucial effective operation of AO hi system for science Pathfinders p RY o Global vision is essential to reduce cost & risks for all s R o l O all challenges alone Fair collaboration is i Ø 1 observatory cannot cope S with h P highly desirable: TMT-GMT-ESO-LBT-Gemini-Keck-WHT-SUBARU. . . Ø Reasonable global 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…
AOF pathfinder Single project structure covering all phases Now in Testing GRAAL GALACSI DSM ASSIST 4 LGSF UT 4 Upgrade NGC SPARTA ( Important R&D component embedded in AOF Project AO 4 ELT - Firenze 27/05/2013 12
ESO AOF: Pathfinding Role for EELT “Soft” benefits: Ø Ø Ø 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: Ø Ø Ø EELT M 4 is directly inspired from the DSM SAGEM benefits from the synergy of thin shells (DSM, proto M 4, M 4 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 < 1 e- RON detector @ 1. 35 k. Hz !!! (with help from community: Ocam, First. Light)
Validate control strategy: AOF as 1 st step ØAOF control/operation strategy good starting point for end-to-end control strategy of ELT Ø SCAO Ø GLAO Ø LTAO Ø ELT more complex though Ø Segmented M 1 Ø 5 mirror design to control Ø Less rigid structure Ø LGS operation more complex Ø Telescope metrology overlaps with AO metrologies Ø MCAO with one DM in telescope
Validate end-to-end acquisition sequence (i. e AOF)
TELESCOPE AO DESIGN & TECHNOLOGY DEVELOPMENT
Adaptive 2. 5 m M 4 unit for 39 m 4974 contactless actuators in optical area Max 160 µm stroke 31. 5 mm pitch, triangular pattern 2480/2387 mm diameter Segmented Zerodur 1. 95 mm thin shell (6 petals) Backplate in Zerodur/Si. C TBC Removable Actuator Brick design (198 bricks) On board M 4 electronics Remote M 4 Control System Flex joint hexapods for M 4 Positioning System Large bearing + cable wrap for Nasmyth selector Mass: 10 tons Power: 8. 4 k. W
M 4 Unit Preliminary Design Contract n Mirror technology optimization: n Development of new concepts for more reliable co-located sensors (more reliable electrical interface, easier installation) applicable to both glass and Si. C M 4 Unit solutions n New design of Brick interfaces to fulfill Si. C manufacturing uncertainties n Demonstration prototype design on-going n Next steps: Demonstration prototype development & Completion of the Preliminary Design
New Actuator bricks design The actual design of the brick is the one that will be tested on the updated demonstration prototype
M 4 Demonstration Prototype (DP) design The DP is representative of most critical aspects of the M 4 U: bricks, Reference body design, shell, actuator pattern, cophasing, actuator/capsens, cooling plant, local control system. 222 actuators 453. 2 x 796 x 300 mm
Error budget estimate for M 4 unit only
2. 5 m M 5 Tip-tilt Unit prototype LCS Ø 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
Instruments & Modules SCAO CAM MCAO SCAO IFU LTAO(GLAO) LTAO – not in cons. phase MIR SCAO 23
From Single to Multi-Conjugate AO for MICADO ØSCAO: 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) Ø Wavefront sensor (type depending on performance & dynamic range) ØM 4 adaptive mirror corrector (baseline fitting error 142 nm rms) ~50 cm sampling on M 1 ØAdditional telescope error budget to be taken into account. ØMCAO: 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)
MAORY Strehl performance (0. 8” seeing) Ø Ø Ø Ø 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 4 km, 12. 7 km Two output ports § Sky coverage Galactic Pole § No telescope error budget included yet
MAORY ensquared energy performance Performance to be updated for 39 m telescope Telescope error budget to be added
MAORY for MICADO on-going work n Managerial: Ø Phase A study Nov 2007 – Dec 2009 Ø MCAO module approved by ESO as part of first-light instrumentation to serve EELT diffraction-limited camera MICADO; however awaiting from E-ELT funding Ø Project plan for next phases under consolidation Ø Negotiations between ESO and INAF (lead institute) are well advanced Ø INAF is supporting the project through its Directorate of Science Ø Current Consortium organization: INAF; Durham Univ; Obs. de Paris/LESIA; ESO
MAORY related on-going work I n Consolidation of 20 W Raman fiber laser developed by ESO/TOPTICA n MAORY optical design trade-offs: alternative DM sizes, ADC, dichroic, LGS WFSs… n Sodium density profile measurements on-axis and in Fo. V (UBC collaboration n E 2 V Manufacturing of WFS detector: CMOS 840^2 pixels with 4 e. RON, 700 Hz n Test controller development for the detector above: LAM & ESO GMT? n Smart algorithms for MCAO… reconstruction in collaboration with Linz team 1377 act. Piezo DM for SPHERE with its drive electronics
MAORY related on-going work II n Laser spot truncation in SH Wf. Sing see Poster Miska et al. n IR 320 x 256 e. APD array required for low WFSing in MAORY, LTAO, SCAO? n Medium size piezo-DM: addressing the recent DM manufacturing obsolescence problem in collaboration with TMT & CILAS n Alternative DM solutions: XINETICS, MZA, MG-ADS n 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
Sodium spot elongation truncation using full tomography information Triangle: Non Gaussian, 2 x 2 NGS, Diamond: 6 x 6 NGS Frim 3 D 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
WFS detectors & controllers NIR SELEX detector GRAVITY 320 x 256 e. APD array RON<3 e @ 1 k frames/s; 47 Kelvin Low order WFS for MAORY-LTAO But also RAPID @ LETI E 2 V + LAM Potential detector for SCAO? 240 x 240 pixels RON 0. 2 e @ 1. 5 k. Hz E 2 V 840 x 840 pixels; 24 -μ pixels RON 3 e @ 700 Hz frame/s delivery Q 4/2013 -Q 1/2014 1. 6 k x 1. 6 k? 31
Wavefront sensing CMOS detector Pixel number Detector technology Pixel Pitch Pixel topology Sub-aperture Array architecture Pixel full well Read noise including ADCs configuration Frame rate “Natural Guide Star Detector” NGSD - 880 x 840 pixels with 840 x 840 sensitive pixels Thinned backside illuminated CMOS 0. 18µm 24µm 4 T pinned photodiode pixel 20 x 20 pixels 42 x 42 sub-apertures of 20 x 20 pixels 4000 e< 3. 0 e-RMS 20 x 880 column ADCs, 9 (goal 10) bits 700 fps up to 1000 fps with degraded performance 32
Deformable mirror & RTC path finders RTC box Co-processing cluster CILAS 1370 actuators piezo DM with 4. 5 mm pitch LGS tomography with 4 LGS WFSs 40 x 40 @ 1 k. Hz
Single conjugate & Laser Tomography AO for HARMONI Ø SCAO: Proposed as part of HARMONI, a complementary AO capability for highest performance on “bright” targets: Solar system, High contrast science, GC… Ø Wavefront sensor (optimized for high contrast, differential tracking capability, …) Ø wavefront sensor: Visible or IR or both? ØM 4 adaptive mirror corrector (baseline fitting error 142 nm rms) ~50 cm sampling on M 1 Ø GLAO: Enhanced seeing capability using NGS wavefront sensors? : Earliest galaxies? 60” Ø LTAO: High throughput, low emissivity, high sky coverage, “High” Sr performance required for faint targets: QSOs, GRBs, High-z G, etc… Ø 6 Laser Guide stars side launched 2’ diameter Ø 2 IR Natural Guide Star corrected with μDM Ø Uses M 4 adaptive mirror (baseline fitting error 142 nm rms) Ø High throughput & low emissivity NGS LGS 120” 4. 2’
Trade-offs on number / position of LGSs LTAO: 6 LGS, 4 laser launch stations (LLS), TT stars close to center of FOV 500 Hz, 500 iterations, 2 frames delay Seeing 0. 8’’, L 0=25 m, tau 0~3 ms Importance of Cn 2 profile assumptions for performance estimates M. Sarazin et al. 9 layers simulated, 9 layers reconstructed (unless otherwise noted)
Single conjugate and Laser Tomography AO for HARMONI ØSemi-analytic simulations for 39 m telescope, LGSs @ 1’ (radius), 6 LGSs Ø 40 atmospheric layers simulated, 7 reconstructed ØPSF available for different wavelengths under request: 0. 8, 1. 0, 1. 2, 1. 6, 2. 2, 10. 0 um Ø On-axis PSF ØWith and without telescope WFE (very preliminary error budget) ØSeeing=0. 67 @ 30 degrees ØContain some “reasonable” TT jitter (± 3 mas rms); pessimistic (TBC)? telescope wind-skake & optimum control of low order modes critical Sr(K) =54% Sr(K) = 48. 5 % Without telescope WFE With telescope WFE Courtesy: Le Louarn-ONERA
LTAO performance (from Phase A 42 m) NOMINAL CONDITION; Sseeing = 0. 8; Zenith = 0°; θ 0 = 2. 08" 900 1250 1650 2200 3500 4800 10500 Width 10 mas 10, 3 21, 1 26, 4 17, 8 13, 7 3, 9 Width 20 mas 15, 1 32, 1 42, 5 48, 5 45, 6 37 14, 3 Width 40 mas 18, 2 37, 8 53, 6 63, 8 62, 8 61 35, 1 Width 60 mas 22, 4 40, 5 56, 3 67, 8 75, 9 69, 1 54, 2 Width 80 mas 23, 2 42, 4 58, 2 70, 2 79, 8 80, 1 63, 8 Width 100 mas 25, 6 44, 8 59, 5 71, 7 81, 3 84, 6 67, 5 Strehl Ratio (%) 5, 5 18, 8 35, 3 52, 7 75, 6 90, 5 96, 9 HARMONI / SIMPLE FWHM (seeing limited) [mas] 646 609 586 546 483 442 357 METIS FWHM (ATLAS) [mas] 8, 2 9 10, 1 12, 1 17, 6 23, 7 49, 1 OPTIMOS / EAGLE like FWHM (Diffraction) [mas] 4, 4 6, 1 8, 1 10, 8 17, 2 23, 6 49, 6 lambda (nm) Ensquared Energy (%) Without telescope error budget to be updated for 39 m ATLAS sky coverage Perf SC (pole) 52 % SR in K 92 % 40 % SR in K 96% 35 % SR in K 97% 13 % SR in K 100 %
Instrumentation arrangement optimization on E-ELT Nasmyth platform n Impact of telescope design change (42 39 m) n Design optomechnical implementation of telescope metrology, LTAO WFSing, and instrument pre-optics to ensure optimum configuration n Ensure good maintenance access on whole Nasmyth platform n Progress on end-to-end Wavefront control strategy to ensure completeness of metrology & AO sensor requirements n Major work on-going!
On-going work for LTAO implementation at Nasmyth I
Option 3 – Gravity invariant cryostat Big optics, but all static
From SCAO to LTAO for METIS SCAO n Excellent on-axis n Integrated in METIS Ø Minimize residual jitter n ‘simple’ first light AO LTAO n Wide(r) field performance n Accepts fainter GS(s) Ø Increased sky coverage n LGS configuration trade-off on-going
SCAO for METIS n SCAO internal to METIS Ø Cold, low (M)IR background n Dichroic first optic inside METIS Ø Cold! Ø Splits at ~2. 5 micron Ø Full METIS field ~18 x 18” n Large field selector Ø Full METIS field Ø Allows or field de-rotation Dichroic ELT Focus METIS Entrance Window n ~40 x 40 sub-apertures n IR WFS Ø Embedded sources Ø Selex experience Gravity n Pyramid WFS Ø Detector available Ø But extended sources? Field Selector ADC? Pupil de-rotator
2. 2 µm 27 May 2013 LTAO 3. 7 µm Simulations 10 µm LTAO Simulations rio a n e se sc AO Only ca t s e B ESO Octopus Simulations/Miska Le Louarn AO + Telescope Only
Next steps n Preliminary design of M 4 unit n Consolidation of MAORY Project plan for next phases n Pursue technology development for MAORY n Optical design trade-off incl. 39 m update n Update Nasmyth platform configuration: telescope metrology- LTAO – HARMONI & METIS n Update performance estimates/error budgets for the different AO capabilities n Consolidate interfaces with instruments
Conclusions n An aggressive AO program is being developed for the VLT n AO pathfinders for E-ELT are on-going @ VLT, WHT, … n Major efforts & collaborations to bring key technologies to n n 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.
THANK YOU for your attention
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