adaptive optics road map an adaptive optics road map presentation to the aura board 7 february 2001...

Adaptive Optics Road Map

An Adaptive Optics Road An Adaptive Optics Road MapMap

Presentation to the AURA Presentation to the AURA BoardBoard

7 February 20017 February 2001

A Renaissance in Groundbased A Renaissance in Groundbased IR (even Optical) Astronomy?IR (even Optical) Astronomy?

Based on presentation to the NSFby Steve Strom


HISTORICAL CONTEXTHISTORICAL CONTEXT

Adaptive optics: one of the major advances Adaptive optics: one of the major advances in in telescope technology of the 20telescope technology of the 20thth century century

“ “comparable to the invention of the telescope”comparable to the invention of the telescope”

AO systems to date demonstrate its potential AO systems to date demonstrate its potential to:to:– Deliver high fidelity, diffraction-limited imagesDeliver high fidelity, diffraction-limited images– Enable large gains in sensitivity Enable large gains in sensitivity – Reduce the size of instrumentsReduce the size of instruments

Science enabled by AO is impressiveScience enabled by AO is impressive– Imaging lava flows on Io; storms on Neptune; Imaging lava flows on Io; storms on Neptune; – Imaging accretion disks; precessing jets in YSOsImaging accretion disks; precessing jets in YSOs– Resolving Dense galactic and globular clustersResolving Dense galactic and globular clusters– Measuring stellar fluxes; colors in nearby galactic Measuring stellar fluxes; colors in nearby galactic

nucleinuclei


However…..However…..

Only 1% – 3% of the sky is accessible to Only 1% – 3% of the sky is accessible to current AO systemscurrent AO systems

Laser systems are still Laser systems are still VERYVERY expensive (and expensive (and immature technologies) immature technologies)

Detector technologies are still limiting Detector technologies are still limiting performanceperformance

Data reduction techniques need to be better Data reduction techniques need to be better understood (or more widely disseminated)understood (or more widely disseminated)

The full scientific potential of AO has yet to The full scientific potential of AO has yet to be realized – need 1 – 2 arcminute corrected be realized – need 1 – 2 arcminute corrected FOV’sFOV’s

AO is the enabling technology for the “next AO is the enabling technology for the “next generation” of (extremely) large generation” of (extremely) large groundbased telescopes groundbased telescopes


Progress to “Progress to “second second generationgeneration” Adaptive ” Adaptive

OpticsOptics

ALFA AOSystem

Sodium Laser result S ~ 0.2, within a factor of 2 of the predicted result (S= 0.4)

And now Lick is Getting S ~ 0.7


Unfortunately Sodium Unfortunately Sodium Lasers are not a mature Lasers are not a mature

technologytechnology


State-of-the-art is still State-of-the-art is still complexcomplex

- Keck’s laser room (one - Keck’s laser room (one wall)wall)


Conclusions (circa 2001)Conclusions (circa 2001) We are entering a decade of unparalleled growth in the We are entering a decade of unparalleled growth in the

competitiveness of ground-based O/IR astronomycompetitiveness of ground-based O/IR astronomy Adaptive Optics will be largely responsible for growthAdaptive Optics will be largely responsible for growth The US and Gemini communities have a unique lead in Adaptive The US and Gemini communities have a unique lead in Adaptive

OpticsOptics However the lack of a mature Sodium Laser technology represents However the lack of a mature Sodium Laser technology represents

an effective “log-jam” in the further development of Adaptive Opticsan effective “log-jam” in the further development of Adaptive Optics The problem Gemini faces, in common with other AO programs, is The problem Gemini faces, in common with other AO programs, is

that the non-recurring costs of developing viable, facility class that the non-recurring costs of developing viable, facility class lasers for such systems are currently beyond the resources of any lasers for such systems are currently beyond the resources of any of the major adaptive optics programsof the major adaptive optics programs

A focused, community wide effort (Gemini, CfAO, USAF) will lead to A focused, community wide effort (Gemini, CfAO, USAF) will lead to “turn-key” “turn-key” affordableaffordable Sodium Lasers for Sodium Lasers for allall grounbased telescopes grounbased telescopes

This will enable MCAO and the ‘Next Generation’ 30m - 100m This will enable MCAO and the ‘Next Generation’ 30m - 100m telescopestelescopes


Some drawbacks of Some drawbacks of “classical” AO“classical” AO

Simulation on Simulation on an 8m an 8m telescope, H telescope, H Band Band (1.6 um)(1.6 um)

Atmospheric Atmospheric spatial spatial decorrelation decorrelation limits effective limits effective FOVFOV

AO correction AO correction requires a requires a bright starbright star

Sky coverage Sky coverage limited tolimited to0.1% - 1% of 0.1% - 1% of sky sky


Some drawbacks of Some drawbacks of “classical” AO“classical” AO

Variation in Variation in Point Spread Point Spread Function (PSF) Function (PSF) across the field across the field of view of view complicates the complicates the quantitative quantitative interpretation interpretation of of observations in observations in dense fields or dense fields or spatially complex spatially complex objects objects


Effectiveness of MCAOEffectiveness of MCAO

Numerical Numerical simulations:simulations:

5 Natural 5 Natural guide starsguide stars

5 Wavefront 5 Wavefront sensorssensors

2 mirrors2 mirrors 8 turbulence 8 turbulence

layerslayers MK MK

turbulence turbulence profileprofile

Field of view Field of view ~ 1.2’ ~ 1.2’

H bandH band


Modeling verses DataModeling verses Data

20 arcsec

M15: PSF variations and stability measured as predicted

GEMINI AO Data

Mod

el R

e su l

ts

2.5 arc min.


Quantitative AO Corrected Data Quantitative AO Corrected Data

• AO performance can be well modeled• Quantitative predictions confirmed by observations

• AO is now a valuable scientific tool:

• predicted S/N gains now being realized

• measured photometric errors in crowded fields ~ 2%

Rigaut et al 2001


The Realm of MCAOThe Realm of MCAO MCAO vs CAO:MCAO vs CAO:

– Field of view, gain in Field of view, gain in area: Jarea: J20-80 x, K20-80 x, K10-10-20 x, depending on 20 x, depending on criteria and conditions.criteria and conditions.

– Photometric Photometric performance: performance: photometric accuracy photometric accuracy prop to Strehl variations prop to Strehl variations in the field. MCAO ~ in the field. MCAO ~ CAO / 10, i.e. for CAO / 10, i.e. for accuracy of 5% for CAO, accuracy of 5% for CAO, MCAO gets to 0.5% -> MCAO gets to 0.5% -> 0.01 mag on a CMD.0.01 mag on a CMD. 600 5

010

20

30

40[arcsec]

MCAO

AO1/2 FoV

1/2 FoV

Realms of MCAO/CAORealms of MCAO/CAO

Field

of

vie

w

[a

rcse

cond

s]

Photometric accuracy [mag]

0.010.050.1 0.005

10

01

01 CAO

MCAO

Keck

PUEO

KeckESO

GSAO

HK

Milky Way

programsNearby

Galaxies

Distant Galaxies


First test of tomographic First test of tomographic techniquetechnique

Ragazzoni et al, 2000, Ragazzoni et al, 2000, Nature 403, 54Nature 403, 54

Collected optical data on Collected optical data on a constellation of 4 starsa constellation of 4 stars

Used tomographic Used tomographic analysis from outer analysis from outer three to predict phase three to predict phase errors of the central starerrors of the central star

Tomographic Tomographic calculations correctly calculations correctly estimated the estimated the atmospheric phases atmospheric phases errors to an accuracy of errors to an accuracy of 92%92%– better than classical AObetter than classical AO– MCAO can be made to MCAO can be made to

workwork


Sodium Laser Sodium Laser at Chileat Chile


The Southern Sodium The Southern Sodium Layer - Preliminary Layer - Preliminary

resultsresults

February 11, 2001


ALTAIR

Unchallenged

“NGST class” science

Laser Development timescales Laser Development timescales in contextin context

2000 2010

ALMAALMA

Keck-Inter.

Keck I&IIUT1-UT4 VLT-I HET LBT

NGST

Gemini-N

Gemini-S

Hokupa’aALTAIR+LGS

‘03 MCAOHokupa’a-II


Laser Development Laser Development timescales in contexttimescales in context

2000 2010

ALMAALMA

Keck-Inter.

Keck I&IIUT1-UT4 VLT-I HET LBT

OWL

20152000 2010

MAXAT CELT

NGST

GSMT

Gemini-N

Gemini-S

Hokupa’aALTAIR+LGS

‘03 GAOS MCAO

2nd Generation Telescopes

Hokupa’a-II


The Groundbased Scientific The Groundbased Scientific ImpactImpact

- - Relative S/N Gain of groundbased Relative S/N Gain of groundbased diffraction limiteddiffraction limited 20m,30m, 50m and 100m 20m,30m, 50m and 100m

telescopes compared to NGSTtelescopes compared to NGST

Gro

un

db

ased

ad

van

tag

eN

GS

T a

dva

nta

ge100m

50m 30m 20m

S/N x 10

Spectroscopy, vSpectroscopy, vres res = 30 kms/s= 30 kms/s


ADAPTIVE OPTICS:ADAPTIVE OPTICS:A ROADMAP FOR THE NEXT A ROADMAP FOR THE NEXT

DECADEDECADE

Based on presentation by CfAO and Based on presentation by CfAO and NOAO/NIO on behalf of the US AO NOAO/NIO on behalf of the US AO

communitycommunity

27 APR 200027 APR 2000


CHALLENGESCHALLENGES

Develop new systems approachesDevelop new systems approaches– Increase sky coverage/Strehl through use Increase sky coverage/Strehl through use

of LGSof LGS– Enable wider fields through use of MCAOEnable wider fields through use of MCAO

Develop key componentsDevelop key components– Reliable, high power lasersReliable, high power lasers– Advanced wavefront sensors and Advanced wavefront sensors and

deformable mirrorsdeformable mirrors– Fast detectorsFast detectors

Advance understanding of Advance understanding of atmospheric turbulenceatmospheric turbulence– Understand turbulence; Sodium layer Understand turbulence; Sodium layer

excitationexcitation

NB: AO advances NB: AO advances required required for d >> 10m for d >> 10m

telescopestelescopes


TOWARD AN AO ROADMAPTOWARD AN AO ROADMAP

Community workshop held on 13/14 Community workshop held on 13/14 DEC in TucsonDEC in Tucson– Co-sponsored by CfAO and NOAOCo-sponsored by CfAO and NOAO

Goals:Goals:– Prepare a 10 year roadmap for NSF Prepare a 10 year roadmap for NSF

investment in AOinvestment in AO• new systems approaches new systems approaches • systems design issues systems design issues • technology investmentstechnology investments• subsystem developmentssubsystem developments• software issuessoftware issues• key investment areas and associated key investment areas and associated

milestonesmilestones– Define a process for Define a process for

implementing/updating the roadmapimplementing/updating the roadmap


KEY TECHNOLOGIESKEY TECHNOLOGIES

Proposed Investment:Proposed Investment:

– Concept studies for next generation Concept studies for next generation telescopestelescopes• identify the role of AO identify the role of AO

Expected Return:Expected Return:

– Deeper understanding of the relative Deeper understanding of the relative priorities of roadmap investments as the priorities of roadmap investments as the decade unfoldsdecade unfolds



Proposed Investment:Proposed Investment:– develop reliable, affordable sodium lasers develop reliable, affordable sodium lasers

(10-50 W)(10-50 W)– support R&D on Rayleigh beacons support R&D on Rayleigh beacons

Expected Return:Expected Return:– greatly accelerated implementation of greatly accelerated implementation of

laser beacons on extant telescopeslaser beacons on extant telescopes– wider field correction through use of wider field correction through use of

MCAOMCAO– all sky coverage at increased Strehlall sky coverage at increased Strehl– extension of AO correction to shorter extension of AO correction to shorter

wavelengthswavelengths



Proposed Investment:Proposed Investment:– prototyping and testing of wavefront correction elementsprototyping and testing of wavefront correction elements

• curved opticscurved optics• adaptive secondaries and primariesadaptive secondaries and primaries• transmissive opticstransmissive optics• higher order deformable mirrorshigher order deformable mirrors

Expected Return:Expected Return:– improved optical simplicity and efficiencyimproved optical simplicity and efficiency– reduced thermal backgroundreduced thermal background– simplified control systemssimplified control systems– enhanced wavefront qualityenhanced wavefront quality




– faster, lower noise detectors with more faster, lower noise detectors with more pixels and broader wavelength coverage pixels and broader wavelength coverage for wavefront sensingfor wavefront sensing


– improved AO performance with both improved AO performance with both natural and laser reference beaconsnatural and laser reference beacons




– advanced numerical methods for advanced numerical methods for computing optimum corrections for computing optimum corrections for inferred wavefront distortionsinferred wavefront distortions


– enhanced corrected field of viewenhanced corrected field of view– improved uniformity of image quality over improved uniformity of image quality over

large FOVlarge FOV




– site-specific monitoring campaignssite-specific monitoring campaigns– instrument packages for real-time support of AO systemsinstrument packages for real-time support of AO systems


– site characterization for design of optimum AO systemssite characterization for design of optimum AO systems– site selection for next generation telescope(s)site selection for next generation telescope(s)




– model AO system performancemodel AO system performance– evaluate/validate competitive approaches to modelingevaluate/validate competitive approaches to modeling


– confidence in predictions from modelingconfidence in predictions from modeling– improved systems approachesimproved systems approaches




– support of concept studies and workshops support of concept studies and workshops to explore instrumentation design in the AO to explore instrumentation design in the AO eraera


– instrument design and performance instrument design and performance matched to opportunities provided by AOmatched to opportunities provided by AO


SCHEDULE FOR KEY SCHEDULE FOR KEY ACTIVITIESACTIVITIES

Site MonitoringSite Monitoring

– 20012001: Begin 3 year program of site testing : Begin 3 year program of site testing to provide a database for AO system to provide a database for AO system modelingmodeling

– 2002: 2002: Deploy instruments for Na-layer Deploy instruments for Na-layer monitoringmonitoring

– 2003: 2003: Deploy initial instruments for Deploy initial instruments for monitoring turbulence in real timemonitoring turbulence in real time

– 2004: 2004: Develop second-generation Develop second-generation turbulence monitoring instrumentsturbulence monitoring instruments

– 2004: 2004: Deploy instrumentation for long-term Deploy instrumentation for long-term studies at several promising sites for next studies at several promising sites for next generation telescopesgeneration telescopes



Systems DesignsSystems Designs

– 20012001--2003:2003: Solicit candidate designs for AO Solicit candidate designs for AO systems on 30-m class telescopessystems on 30-m class telescopes

– 2004-2006: 2004-2006: Test at least two design Test at least two design concepts in the lab or on extant telescopesconcepts in the lab or on extant telescopes

– 2006-2010: 2006-2010: Build one full-up AO system to Build one full-up AO system to test advanced concepts on 8-10m test advanced concepts on 8-10m telescopes in service of implementation on telescopes in service of implementation on a 30-m telescopesa 30-m telescopes

– 2009-2010: 2009-2010: Develop merged design of 30-Develop merged design of 30-100m telescope and advanced AO system100m telescope and advanced AO system



Deformable MirrorsDeformable Mirrors

– 20012001: Draft plan for developing deformable : Draft plan for developing deformable mirror technologies (~10,000 degrees of mirror technologies (~10,000 degrees of freedom)freedom)

– 2002-2004: 2002-2004: Construct modest-sized Construct modest-sized prototypesprototypes

– 2005-2007: 2005-2007: Build two or three deformable Build two or three deformable mirrors using scalable technologiesmirrors using scalable technologies



Wavefront-sensing detectorsWavefront-sensing detectors

– 20012001: Facilitate foundry runs for fast, low-: Facilitate foundry runs for fast, low-noise detectors for wavefront sensing in the noise detectors for wavefront sensing in the visible and near-IRvisible and near-IR

– 2002-2003: 2002-2003: Take delivery and test in existing Take delivery and test in existing AO systemsAO systems

– 2004-2006: 2004-2006: Fund and test the most Fund and test the most promising technology for 512x512 promising technology for 512x512 detectors (for 30-100m application)detectors (for 30-100m application)


Investment RequiredInvestment Required

AO Systems for GSMT will cost ~ $100M

10 year plan required 2002 - 2012

DRAFTDRAFT

adaptive optics road map an adaptive optics road map presentation to the aura board 7 february 2001...

Documents

adaptive optics road

development of adaptive

major adaptive optics

sky slide

ao programs

telescope ao systems

wall slide

mature technology slide