MULTIPLE OBJECT ADAPTIVE OPTICSMixed NGS/LGS Tomography

Tim Morris (Durham University, UK)

and

Eric Gendron, Alastair Basden, Olivier Martin, David Henry, Zoltan Hubert, Gaetano Sivo, Damien Gratadour, Fanny Chemla, Arnaud Sevin, Matthieu Cohen, Eddy Younger, Fabrice Vidal, James Osborn, Richard Wilson, Tim Butterley, Urban Bitenc, Dani Guzman, Javier de Cos Juez, Andrew Reeves, Nazim Bharmal, Henri-Francois Raynaud, Caroline Kulcsar, Jean-Marc Conan, Jean-Michel Huet, Denis Perret, Colin Dickson, David Atkinson, Tom Baillie, Andy Longmore, Stephen Todd, David Anderson, Colin Bradley, Olivier Lardiere, Gordon Talbot, Simon Morris, Richard Myers and Gerard Rousset

Overview• MOAO instrumentation• CANARY Status• CANARY Results

• SCAO, GLAO, MOAO, LTAO• Bench and on-sky

• CANARY development

MOAO instrumentation• First on-sky open-loop AO systems used on-axis guide

star to control a single on-axis DM• ViLLaGeS1 and VOLT2 demonstrated open-loop AO on-sky in 2007

& 2008 respectively• Proved that open-loop control of AO systems was feasible

• Laboratory test benches were developed that were capable of investigating wavefront tomography and control• UCO/LAO tomographic AO testbench3 at UCSC• SESAME at the Observatoire de Paris

• Combining open-loop control with wavefront tomography gave rise to instrument concepts such as FALCON and EAGLE

1. Gavel et al, Proc. SPIE Vol. 6888, p688804 (2008)2. Andersen et al, Proc. SPIE Vol. 7015, p70150H (2008)

3. Ammons et al, Proc. SPIE Vol. 6272, p627202 (2006)

RAVEN• RAVEN is a 2-channel

MOAO system being built for the Subaru telescope.• Feeds existing slit-based

spectrograph

• Uses 3 off-axis NGS within a 3.5’ FOV• 15th magnitude NGS goal

• Can also use Subaru’s on-axis sodium LGS

• First light planned for May 2014

RAVEN

No AO

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Open-loop GLAO

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Closed-loop AO

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Science camera images (=1.0-1.7m) after 1s of turbulence history. NGS asterism radius = 40 arcsec.

• Currently assembled in the UVic AO lab and undergoing initial laboratory AO testing• SCAO > MOAO > GLAO

• For more information see posters by:• Olivier Lardière (RAVEN status)• Kate Jackson (RAVEN tomography)

CANARY• An open-loop tomographic AO demonstrator on the 4.2m William

Herschel Telescope in La Palma• Split into 3 phases of increasing complexity

• Phase A: NGS-only open-loop tomographic AO (2008-2010)• Phase B: Mixed NGS and LGS open-loop tomographic AO (2010-2013)

• B1: Single LGS• B2: Multiple LGS

• Phase C: Mixed NGS and LGS open-loop tomographic AO with a closed-loop GLAO/LTAO DM (2014+)

3’ DEROTATED TECHNICAL FIELD OF VIEW

3 OFF-AXIS OPEN-LOOP NGS UP TO MV ~ 11-12

ON-AXIS CORRECTED SCIENCE/VERIFICATION PATH

CANARY so far...

• Phase B1 (3 NGS + 1 LGS) commissioned June 2012• Almost identical to RAVEN configuration (except on a 4m telescope with a

Rayleigh LGS)

• Phase B2 (3 NGS + 4 LGS) first on-sky commissioning run finished yesterday morning

• Phase A (NGS only) completed 2010• Seeing-limited (NoAO) (SR=1%)• GLAO (SR=9%)• MOAO (SR=19.4%)• SCAO (SR=23.8%)

Asterism 47 and Phase A AO performance at 1.53μm

CANARY Phase B1• Single LGS that could be positioned anywhere within a ~1’ FOV

• In practice, LGS remained on-axis

• LGS altitude was fixed at 13.5km• Provided photon return ‘safety margin’

13.5km distant LGS WFS image750m range gate

~4” per subaperture

CANARY Phase B2: 4LGS WFS• 3 nights on-sky with the

Phase B2 system from 23rd to 25th May• 6 nights scheduled in July

• New for Phase B2: 4LGS WFS• 128 x 128 pixel camera from

MIT-LL/Scimeasure• >1000:1 contrast ratio integrated

shutter• Pyramid-based asterism

selection• 21km central LGS focal

distance• 23” radius asterism• 1.5km range gate depth

• 1.2” elongation

ACQUISITION CAMERA

PYRAMID

FIELD STOP

LENSLET

LGS WFS

Rayleigh Fratricide• Laser outputs more light at pulse rates > 10kHz• Minimum laser pulse rate defines maximum altitude• 10kHz allows a maximum LGS focal distance of 15000m

• Optical system defines what altitudes can be observed

CANARY Phase B2: Profiling• New Stereo-SCIDAR turbulence profiler in addition to

SLODAR and CANARY WFSs• See talk by James Osborn on Wednesday 15:20

SCIDAR @ JKT

Profiling

• SLODAR• Up to ~6km using existing

binary targets• Total turbulence strength• Monitoring

• Stereo-SCIDAR• High vertical

resolution • ~200m (at altitudes

>0km) • Wind velocities

Relative turbulence strength (%)

Alti

tude

(m

)

• CANARY Open-loop WFSs• Up to 4 NGS and LGS

for multi-baseline SLODAR profiling

• Takes telescope time

CANARY results

• Comprehensive analysis of Phase A/B results will be presented in this afternoon’s talk by Olivier Martin (@ 1700)

• Results of the LQG on-sky reconstructor are going to be presented by Gaetano Sivo on Friday

• Here we present initial results from the Phase B2 run

CANARY Phase B2 system at the WHT Nasmyth platform

NGS & LGS MOAO• Three star test asterism (Ast T1)

• RA: 13 41 38.2, Dec: +07 36 21

• Mb= 10.4, 11, 11.1

• 3-layer tomographic reconstructor fitted• NIR PSFs recorded at 1530nm

29.8” 56.6”

22.8

”

Relative turbulence strength (%)A

ltitu

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m)GLAO

SR = 9.9%

SCAO

SR = 21.5%

NGS + LGS MOAO

SR = 15.2%

NGS & LGS MOAOS

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SCAO

MOAO(4 LGS + 2

NGS)

GLAO(4 LGS + 2

NGS)

Results from single dataset taken switching between SCAO, combined NGS & LGS tomography and combined NGS & LGS GLAO

NGS & LGS MOAO

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Atmospheric r0 (m)

• A few caveats:• CANARY is a low-order 7x7 system • High frequency errors in the DM surface

leave us with a large residual static error

• A few obvious points:• SCAO > MOAO > GLAO• GLAO still pretty good!

• A few less obvious points:• CANARY data has shown WHT

performance dominated by GL turbulence

• Quasi-static error term affecting MOAO results

• This term is difficult to calibrate and is partially due to varying field aberrations caused by the derotator

Open-loop LTAO• CANARY LGS asterism diameter has been

selected to optimise on-axis performance• Optimal performance is found when LGS are

positioned at ~ 1 pupil diameter at altitude

• No fundamental difference between CANARY 4 LGS MOAO configuration and optimal LTAO configuration• Open-loop operation vs. Pseudo open-loop

Asterism 32

2 Tip-Tilt, 4 LGS

SCAO

SR = 21.6%

LTAO

SR = 14.7%

On-sky tomography testing• Have on-sky data for a wide variety of tomographic

configurations:• SCAO• Mixed NGS and LGS MOAO

• 0 & 4 LGS, 1-3 NGS stars• LGS-only MOAO (Open-loop LTAO)

• 4 LGS, 1-3 TT stars• Mixed NGS and LGS GLAO (open-loop)

• 4 LGS, 1-3 NGS stars• LGS only GLAO (open-loop)

• 4 LGS, 1-3 TT stars

• Have taken corrected datasets for both minimum variance and LQG reconstructors for most of these

• Bench validation using the CANARY telescope simulator is the first step

Bench tomography testing• Turbulence generated using

telescope simulator,• 2 layers at 0 and 5200m• 70% at ground, 30% alt.• r0 = 11 cm, L0≈12 m• Windspeed ≈ 6m/s

• NGS configured to simulate CANARY asterism A47NGS1 -43.4 20.4NGS2 47.3 21.4NGS3 28.3 -28.8

• Square LGS asterism• 21.6’’ off-axis• Altitude 17000m

SCAO

4LGS+3NGS

4LGS+2NGS

4LGS+1NGS

3LGS + 3NGS

2LGS+3NGS

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CANARY: A Flexible Testbench• CANARY doesn’t only demonstrate MOAO!• Reconfigurable optical layout allows many other tests

• New WFSs• LGS WFSing with controlled elongation

• Linux-based RTCS has been readily adapted as the project has progressed

• Many new centroiding techniques• New reconstructors

• Several talks/presentations this week about techniques developed and tested/to-be tested on-sky using CANARY

Topic Who What When

On-sky phase diversity Damien Gratadour Talk Today 17:40

Open-loop tomography Olivier Martin Talk Today 17:00

LQG reconstruction Gaetano Sivo Talk Friday 12:00

Real-time Control Systems Richard Myers Talk Friday 14:20

On-sky CuRe-type reconstructors tests Urban Bitenc Poster

Sodium LGS elongation studies Gerard Rousset Poster

Tomography with Artificial Neural Networks• Using machine learning to generate a robust tomographic

reconstructor• Advantages:

• Includes non-linear effects difficult to model• Single reconstructor optimal for all turbulence profiles

• Disadvantages:• Requires a large amount of training data• Training process can take a long time for large systems

• For CANARY: L&A: 1minute, ANN: 10 minutes

• Valid only for a given asterism• Good for LGS systems!

ANN Tomography

WFS x 3WFS x 3

• Trained an ANN reconstructor using CANARY bench measurements

• Compared to L&A reconstructor trained on a 2-layer atmosphere (0km and 2.8km)

• Reconstructed on-axis WFS slopes whilst changing conjugate altitude of high layer

CANARY future• Phase C1: LTAO (on-sky

May/July 2014)• Design review next week• Reorganisation of the bench to

place WFSs behind DM• Additional figure sensor for

pseudo open-loop operation

• Phase C2: E-ELT configuration MOAO (on-sky 2015)• Closed-loop GLAO DM

(existing low-order DM)• Open-loop MOAO DM (high-

order DM)• High order figure sensor• High order LGS WFSs

p h a s e C e n d - t o - e n d o p t i c a l d e s i g n M C A O m o d e s a n s c a m i c a z . z m xC o n f i g u r a t i o n 1 o f 1

3 D L a y o u tT R U T H1 1 / 0 4 / 2 0 1 3

X

Y

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Photon return

• LGS photon return measured at Phase B1 on a single LGS• Varying RGD makes this

easy!

• Projected to 4 LGS Phase C1/2

• Defines optimal LTAO error at Phase C1

• Defines how many subapertures we can use at Phase C2

Beyond Phase C• Funding has been secured for further on-sky

investigations with CANARY:• Focal plane NIR WFSing• E-ELT scale LGS elongation WFS study

• Several ideas have been proposed for later phases:• Open-loop MCAO demonstration• LGS uplink tomography for tip-tilt determination

• Additional technology demonstrations planned:• On-sky demonstration of AO-coupled integrated photonic

spectrograph

• Always open to new collaborations that will benefit from an on-sky test…

Conclusions• CANARY is now almost in its final configuration with a

world record (?) 8 full frame rate, high-order wavefront sensors

• We have demonstrated mixed NGS and LGS open-loop tomography on-sky• Additional results this afternoon!

• LGS MOAO works and can provide much better performance than LGS GLAO

• Closed-loop LTAO and high-order MOAO on-sky in 2014/15 repsectively

System Growth• CANARY complexity has increased since

initial testing phase in early 2009• Currently have 8 WFS’s , 25 reference

sources and 288 WFS subapertures

Number of WFSsNumber of reference

sourcesNumber of WFS

subapertures

AO4ELTs, Paris 2009 CANARY: NGS/LGS MOAO DEMONSTRATOR

DurhamDurham Richard Myers, Gordon Talbot, Nigel Dipper, Deli Geng, Eddy Younger, Alastair Basden, Richard Myers, Gordon Talbot, Nigel Dipper, Deli Geng, Eddy Younger, Alastair Basden, Colin Dunlop, Nik Looker, Tim Butterley, Laura Young, Simon Blake, Sofia Dimoudi, Paul Colin Dunlop, Nik Looker, Tim Butterley, Laura Young, Simon Blake, Sofia Dimoudi, Paul Clark, Nazim Bharmal, Richard Wilson, Harry Shepherd, James Osborn, Urban Bitenc, Clark, Nazim Bharmal, Richard Wilson, Harry Shepherd, James Osborn, Urban Bitenc, Andrew Reeves, Simon MorrisAndrew Reeves, Simon Morris

Observatoire Observatoire de Parisde Paris

Zoltán Hubert, Gerard Rousset, Eric Gendron, Fabrice Vidal, Damien Gratadour, Aglae Zoltán Hubert, Gerard Rousset, Eric Gendron, Fabrice Vidal, Damien Gratadour, Aglae Kellerer, Michel Marteaud, Fanny Chemla, Phillipe Laporte, Jean-Michel Huet, Matthieu Kellerer, Michel Marteaud, Fanny Chemla, Phillipe Laporte, Jean-Michel Huet, Matthieu Brangier, Olivier Martin, Mathieu Cohen, Denis Perret, Arnaud Sevin, Brangier, Olivier Martin, Mathieu Cohen, Denis Perret, Arnaud Sevin,

UKATCUKATC David Henry, Stephen Todd, Colin Dickson, Brian Stobie, David Atkinson, Tom Bailie, David Henry, Stephen Todd, Colin Dickson, Brian Stobie, David Atkinson, Tom Bailie, Martin Black, Andy LongmoreMartin Black, Andy Longmore

ONERAONERA Jean-Marc ConanJean-Marc Conan, , Thierry Fusco, Clelia Robert, Nicolas VedrenneThierry Fusco, Clelia Robert, Nicolas Vedrenne

INGING Jure Skvarc, Juerg Rey, Neil O’Mahoney, Tibor Agocs, Diego Cano, Don Carlos AbramsJure Skvarc, Juerg Rey, Neil O’Mahoney, Tibor Agocs, Diego Cano, Don Carlos Abrams

IOGSIOGS Caroline Kulscar, Henri-Francois Raynaud, Gaetano SivoCaroline Kulscar, Henri-Francois Raynaud, Gaetano Sivo

OthersOthers Andres Guesalaga (PUC Santiago), Dani Guzman (PUC Santiago), Javier de Cos Juez Andres Guesalaga (PUC Santiago), Dani Guzman (PUC Santiago), Javier de Cos Juez (University of Ovideo)(University of Ovideo)

The CANARY project is supported via the following funding bodiesThe CANARY project is supported via the following funding bodies STFC, UK E-ELT Design StudySTFC, UK E-ELT Design Study EU FP7 Preparatory fund WP9000EU FP7 Preparatory fund WP9000 ANR Maui, INSU, Observatoire de ParisANR Maui, INSU, Observatoire de Paris FP7 OPTICON JRA1FP7 OPTICON JRA1