1. European Southern Observatory European Southern Observatory Enrico Fedrigo © ESO 2008 Garching, 7th October 2008 Enrico Fedrigo Adaptive Optics Systems Instrumentation Software Workshop 2008

2. European Southern Observatory European Southern Observatory © ESO 2008 Page 2 Enrico Fedrigo Overview  Fundamentals of Adaptive Optics  AO general system architecture  Adaptive optics systems  SPARTA Architecture  Main SPARTA  SPARTA Light

3. European Southern Observatory European Southern Observatory © ESO 2008 Page 3 Enrico Fedrigo Fundamentals of Adaptive Optics (i.e.: super short AO Tutorial)

4. European Southern Observatory European Southern Observatory © ESO 2008 Page 4 Enrico Fedrigo Why is Adaptive Optics needed? Even the largest ground-based astronomical telescopes have no better resolution than a 20cm telescope! Even the largest ground-based astronomical telescopes have no better resolution than a 20cm telescope! Turbulence in earth’s atmosphere makes stars twinkle More importantly, turbulence spreads out light; makes it a blob rather than a point

5. European Southern Observatory European Southern Observatory © ESO 2008 Page 5 Enrico Fedrigo Images of a bright star First Light MACAO-VLTI UT2

6. European Southern Observatory European Southern Observatory © ESO 2008 Page 6 Enrico Fedrigo Turbulence arises in several places Measured from a balloon rising through various atmospheric layers

7. European Southern Observatory European Southern Observatory © ESO 2008 Page 7 Enrico Fedrigo Optical consequences of turbulence  Temperature fluctuations in small patches of air cause changes in index of refraction (like many little lenses)  Light rays are refracted many times (by small amounts)  When they reach telescope they are no longer parallel  Hence rays can’t be focused to a point: Parallel light rays Light rays affected by turbulence  blur  Point focus

8. European Southern Observatory European Southern Observatory © ESO 2008 Page 8 Enrico Fedrigo Imaging through a perfect telescope  With no turbulence, FWHM is diffraction limit of telescope, ~ / D ~ / D  Example: / D = 56 milliarc sec (mas) for / D = 56 milliarc sec (mas) for = 2.2  m, D = 8 m = 2.2  m, D = 8 m  With turbulence, image size gets much larger (typically 0.5 - 2 arc sec) FWHM ~ /D in units of /D 1.22 /D Point Spread Function (PSF): intensity profile from point source

9. European Southern Observatory European Southern Observatory © ESO 2008 Page 9 Enrico Fedrigo Effect of turbulence on images size and what AO does  r0 is diameter of the circular pupil for which the diffraction limited image and the seeing limited image have the same angular resolution.  If telescope diameter D >> r0, image size of a point source is ( / r0) >> ( / D)  When AO system performs well, more energy in core  When AO system is stressed (poor seeing), halo contains larger fraction of energy (diameter ~ r0)  Ratio between core and halo varies during night Intensity x Definition of “Strehl”: Ratio of peak intensity to that of “perfect” optical system AO produces point spread functions with a “core” and “halo”

10. European Southern Observatory European Southern Observatory Enrico Fedrigo © ESO 2008  20 arcsec Omega Centauri with MCAO (MAD)

11. European Southern Observatory European Southern Observatory © ESO 2008 Page 11 Enrico Fedrigo AO general system architecture

12. European Southern Observatory European Southern Observatory © ESO 2008 Page 12 Enrico Fedrigo Schematic of adaptive optics system Feedback loop: next cycle corrects the (small) errors of the last cycle

13. European Southern Observatory European Southern Observatory © ESO 2008 Page 13 Enrico Fedrigo How to measure turbulent distortions Shack-Hartmann wavefront sensor: NAOS

14. European Southern Observatory European Southern Observatory © ESO 2008 Page 14 Enrico Fedrigo Deformable Mirrors How a deformable mirror works (idealization) BEFORE AFTER Incoming Wave with Aberration Deformable Mirror Corrected Wavefront In practice, a small deformable mirror with a thin bendable face sheet is used

15. European Southern Observatory European Southern Observatory © ESO 2008 Page 15 Enrico Fedrigo Adaptive Optics Systems

16. European Southern Observatory European Southern Observatory © ESO 2008 Page 16 Enrico Fedrigo SCAO: Single Conjugated AO VLT: NAOS VLT: MACAO VLT: SINFONI VLT: CRIRES E-ELT: not present Telescope Reference Star On axis WFS WFC © E.Marchetti / ESO / 2005 Single Conjugated AO Ground Conj. DM GroundLayer HighAltitudeLayer

17. European Southern Observatory European Southern Observatory © ESO 2008 Page 17 Enrico Fedrigo GLAO: Ground Layer AO VLT: GRAAL VLT: GALACSI E-ELT: telescope system Telescope ReferenceStars WFS WFC © E.Marchetti / ESO / 2005 Ground Layer AO Ground Conj. DM GroundLayer HighAltitudeLayer

18. European Southern Observatory European Southern Observatory © ESO 2008 Page 18 Enrico Fedrigo LTAO: Laser Tomography AO VLT: GALACSI E-ELT: ATLAS Telescope Laser Guide Stars GroundLayer HighAltitudeLayer WFS WFC Laser Tomography AO Camera Ground conj. DM © E.Marchetti / ESO / 2005

19. European Southern Observatory European Southern Observatory © ESO 2008 Page 19 Enrico Fedrigo MCAO: Multi Conjugate AO VLT: MAD VLT: ISIS? E-ELT: MAORY Telescope ReferenceStars WFS WFC © E.Marchetti / ESO / 2005 Star Oriented MCAO Ground Conj. DM Altitude Conj. DM GroundLayer HighAltitudeLayer  Star-oriented  Layer-oriented  Multiple FoV

20. European Southern Observatory European Southern Observatory © ESO 2008 Page 20 Enrico Fedrigo MOAO: Multi-Object AO VLT: FALCON E-ELT: EAGLE FP7: CANARY Telescope ReferenceStars WFS WFC Multi-Object AO Wavefront sensor in pseudo-closed loop + GLAO Narrow field mode DM IFU Wide field mode Ground conj. DM GroundLayer HighAltitudeLayer FoV  Field of research  Many versions

21. European Southern Observatory European Southern Observatory © ESO 2008 Page 21 Enrico Fedrigo XAO: Extreme AO VLT: SPHERE E-ELT: EPICS Telescope Reference Star On axis WFS WFC © E.Marchetti / ESO / 2005 Single Conjugated AO Ground Conj. DM GroundLayer HighAltitudeLayer

22. European Southern Observatory European Southern Observatory © ESO 2008 Page 22 Enrico Fedrigo SPARTA Architecture

23. European Southern Observatory European Southern Observatory © ESO 2008 Page 23 Enrico Fedrigo General AO Control Architecture Data Acquisition Front end Back end DataAcquisitionDataAcquisition SlopeComputationSlopeComputation ReconstructionReconstruction ControlControl Mirrors Control Flat fielding Flat fielding Background subtraction Background subtraction De-scrambling De-scrambling Slope computation Slope computation Equalization Equalization Reference subtraction Reference subtraction Matrix-vector product Matrix-vector product Controller Controller Saturation management Saturation management Piston control Piston control etc. etc.

24. European Southern Observatory European Southern Observatory © ESO 2008 Page 24 Enrico Fedrigo Timing Diagram Definitions 22/09/2008 ESO HQ RTC Timing Diagram with pipelining Integration Time NIntegration Time N+1Integration Time N+2 Readout N First gradient available Reconstruction NCTRL CODE DM RTC latency Total computing latency Total latency First pixel out Detector latency

25. European Southern Observatory European Southern Observatory © ESO 2008 Page 25 Enrico Fedrigo SPARTA Software Architecture Real Time Low Latency Supervisor Cluster WS  FPGA and DSP code  Drivers running on the CPUs  Drivers offer SPARTA-standard TCP/IP interface  VxWorks on CPUs  DDS sources  Gigabit Ethernet  non real-time, but high throughput  Linux / Intel CPUs  Standard Middleware (ACE/TAO)  BLAS + MKL (multi-thr) + ScaLAPACK + FFTW math libraries  IP Data distribution pipeline (OMG-DDS)  Data storage (RAID array)  All intelligent processing here (coordination, calibration, …)  Gigabit Ethernet  CCS Interface  Command Panels  Data display

26. European Southern Observatory European Southern Observatory © ESO 2008 Page 26 Enrico Fedrigo Three blocks with different features Low latency Hard real-time Simple functions Low flexibility High latency Soft real-time Complex functions High flexibility Non real-time High level functions High flexibility SPARTA Architecture

27. European Southern Observatory European Southern Observatory © ESO 2008 Page 27 Enrico Fedrigo RTC box functions Acquisition From pixels to gradients - FPGA - Reconstruction From gradients to mirror deltas - DSP - Control Controller, saturation, Kalman, anti wind-up, Auxiliary loops - AltiVec - Acquisition Secondary sensors - FPGA- SPARTA Architecture

28. European Southern Observatory European Southern Observatory © ESO 2008 Page 28 Enrico Fedrigo Data Processing Data Switch Atmospheric statistics Loop optimisation Performance Estimator Correlation Receiver Graphical server Display Data Storage/Replay

29. European Southern Observatory European Southern Observatory © ESO 2008 Page 29 Enrico Fedrigo SPARTA Hardware

30. European Southern Observatory European Southern Observatory © ESO 2008 Page 30 Enrico Fedrigo SPARTA Hardware

31. European Southern Observatory European Southern Observatory © ESO 2008 Page 31 Enrico Fedrigo SPARTA Hardware

32. European Southern Observatory European Southern Observatory © ESO 2008 Page 32 Enrico Fedrigo SPARTA Light Strong interest in a low-cost SPARTA for the laboratory:  PC-based for low-cost  Flexible to study new algorithms/strategies  Can grow step by step with increasing performance (and cost)  Easier path from lab to instrument (i.e. from low-cost to full SPARTA).  Use same middle level software (supervisor), same interfaces  familiar framework  Use cheap version of input/output devices where possible Strong interest in a scaled-down version of SPARTA for simple AO systems  Use same middle level software (supervisor), same interfaces, a real-time box but lower cost and simpler

33. European Southern Observatory European Southern Observatory © ESO 2008 Page 33 Enrico Fedrigo SPARTA RTC Box Modules WFS CODE ACQ REC CTRL Serial FPDP VLT-ICD-ESO-16100-3668 VLT-SPE-ESO-16100-3729 Serial FPDP VLT-ICD-ESO-16100-3421 Serial FPDP VLT-SPE-ESO-16100-3801 VLT-TRE-ESO-16100-4262 TCP/IP VLT-SPE-ESO-16100-4290 OMG-DDS VLT-TRE-ESO-16100-4624

34. European Southern Observatory European Southern Observatory © ESO 2008 Page 34 Enrico Fedrigo SPARTA Light Specifications Only addresses the Real Time Box  Specifies different hardware  Different interfaces between modules  The rest is SPARTA-compliant  ACQ  REC  CTRL

35. European Southern Observatory European Southern Observatory © ESO 2008 Page 35 Enrico Fedrigo SPARTA Light: cheapest solution

36. European Southern Observatory European Southern Observatory © ESO 2008 Page 36 Enrico Fedrigo Where do we go from here? SystemType#sDoF#mDoFFRQLatencyComplexity MACAOSCAO1601 420300µs1.5 MF NAOSSCAO114x141187480300µs27 MF / 1 SystemType#sDoF#mDoFFRQLatencyComplexity SPHEREXAO140x40113201500150µs5 GF / 180 GRAALGLAO440x40111701000300µs11 GF / 426 GALACSILTAO440x40111701000300µs11 GF / 426  Current systems  Systems under development SystemType#sDoF#mDoFFRQLatencyComplexity Entry levelSCAO184x841500050020%?27 GF / 14 EPICSXAO4200x200140000300020%?8 TF / 640 MAORYMCAO6100x1002121 8000 3000 100020%?2 TF / 150  E-ELT

37. European Southern Observatory European Southern Observatory © ESO 2008 Page 37 Enrico Fedrigo Document List Garching, 7 nd October 2008 #TitleNumberIssue 1SPARTA OverviewVLT-TRE-ESO-16100-42592 2SPARTA System RequirementsVLT-SPE-ESO-16100-43592 3SPARTA GlossaryVLT-TRE-ESO-16100-43702 4SPARTA Software Framework Installation and OperationVLT-TRE-ESO-16100-46231 5SPARTA Hardware Final DesignVLT-TRE-ESO-16100-40102 6SPARTA High-level Software DesignVLT-TRE-ESO-16100-46241 7SPARTA Real-Time Box DesignVLT-TRE-ESO-16100-46251 8SPARTA Linux cluster benchmarksVLT-TRE-ESO-16100-42642 9SPARTA Communication Layer DesignVLT-TRE-ESO-16100-42622 10SPARTA Test StrategyVLT-PLA-ESO-16100-42652 11SPARTA Driver ProtocolVLT-SPE-ESO-16100-42902 12SPARTA WPU Technical SpecificationsVLT-SPE-ESO-16100-38013 13SPARTA WPU Final DesignVLT-TRE-UOD-16100-36081 14SPARTA Stream Simulator tech SpecVLT-SPE-ESO-16100-46431 15 SPARTA CODE Test Tool Technical SpecificationsVLT-SPE-ESO-16100-37431 16SPARTA CODE TT User manual VLT-MAN-ESO-16100-41121 17SPARTA CODE TT Programmer’s Manual VLT-MAN-ESO-16100-41131 18 SPARTA ICD with CODEVLT-ICD-ESO-16100-34216 19 SPARTA NGC SpecificationsVLT-SPE-ESO-16100-37294 20 SPARTA Instrument ICDVLT-ICD-ESO-16100-41343 21 SPARTA for GRAAL Functional SpecificationsVLT-SPE-ESO-16100-41361 22 SPARTA for GRAAL Software DesignVLT-TRE-ESO-16100-41351 23 SPARTA for SAXO Functional SpecificationsVLT-SPE-ESO-16100-42912 24 SPARTA for SAXO Software DesignVLT-TRE-ESO-16100-42921 25 SPARTA for GALACSI Functional SpecificationsVLT-SPE-ESO-16100-43911 26 SPARTA for GALACSI Software DesignVLT-TRE-ESO-16100-38091 27 Reconstructor Data Handling Firmware Design ReportVLT-TRE-ARE-16100-46271 28 Reconstructor Data Handling Firmware Test Plan and ReportVLT-TRE-ARE-16100-46281 29 Back-end Development Design ReportVLT-TRE-ARE-16100-46291 30 Back-end Development Test Plan and ReportVLT-TRE-ARE-16100-46301 31 SPARTA VPF1 Performance ReportVLT-TRE-UOD-16100-42631 32 SPARTA Remote Reset ControlVLT-SPE-ESO-16100-38002 33 SPARTA Specification for the Andor CameraVLT-SPE-ESO-16100-36681 34 SPARTA DSP BenchmarksVLT-TRE-ESO-16100-41391 First 10 documents not yet available: under review

38. European Southern Observatory European Southern Observatory © ESO 2008 Page 38 Enrico Fedrigo