The Anisoplanatic Point Spread Function in Adaptive Optics

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The Anisoplanatic Point Spread Function in
Adaptive Optics

• Matthew Britton
• Caltech Optical Observatories

Seeing Symposium March, 2007
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Anisoplanatism
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Long Exposure OTF

• OTF(r) e-Dapl(r)/2 OTFgs(r)

Dapl(r) depends on
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Turbulence Profile Measurements at Palomar Aug
20, 2005
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(No Transcript)
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AO PSF Variability

• A persistent problem for astronomers in trying to
  obtain quantitative answers from adaptive optics
  observations.
• The primary motivation for the development of
  advanced AO architectures, such as MCAO and MOAO.

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Predicting the Field Dependent Point Spread
Function
OTFgs(r) e-Dapl(r)/2 OTF(r)
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There are no free parameters in this prediction
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Observational Details
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Measured Turbulence ParametersAug 20, 2005
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Observed and Predicted PSFs
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Strehl Ratios vs. Time
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Predicted vs. Measured Strehls
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Fit Residuals
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Differential Photometry
Relative Intensity
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Differential Astrometry
r
q
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A Crowded Field Observation
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Modeling a Crowded Field
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Comments Related to Turbulence Monitoring

• Demonstrates consistency of measured MASS
  profiles and effects of anisoplanatism in AO
  data
• Illustrates the use of turbulence profiles in AO
  data analysis

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Comments Related to Adaptive Optics

• Experimentally demonstrates limitations of the q0
  approximation
• Validates theoretical understanding of
  anisoplanatism

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Comments Related to Astronomy

• Demonstrates predictability of the PSF over an
  arcminute field.
• Demonstrates astronomically interesting levels of
  performance.

Equipment available at many observatories, so
theres opportunity to make progress
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Acknowledgements

• TMT site testing group
• Palomar Observatory Staff
• Center for Adaptive Optics