d = differential photometry = differential astrometry
Differential Photometry
2.12 m .7903 +/- .0004
1.65 m .8316 +/- .0007
Relative Intensity
Differential Astrometry
2.12 m 21.3322 +/- .0006 282.3923 +/- .0011
1.65 m 21.3306 +/-.0012 282.3932 +/- .0023
Observations of a Quadruple
Modelling the Observation
LGS Adaptive Optics
Laser Tilt Indeterminacy
Pilkington 1987 (Nature)
Adaptive Optics with Lasers
LGS PSFs on a 10 m Aperture
Keck LGS observationOf M5
(Courtesy of the CfAO Treasury Survey)
Advanced Wide Field Adaptive Optics
A Preliminary Comment
Field dependence of the AO system performance is a function of:
• Aperture diameter• Observing wavelength• Guide star configuration• How the adaptive mirrors are deployed• Zenith angle• Turbulence conditions (-> time)
Single Laser AO (SLGLAO)
Poor to moderate performance over a modest field
FOV = 70” (D / 30 m)(90 km / h)
Ground Layer AO (GLAO)
Poor performance
Field uniformity
Tomography
Laser Tomography AO (LTAO)
Good performance on axis
Multiconjugate AO (MCAO)
Good performance over 30” field
Multiobject AO (MOAO)
Intermediate performance over 5’ field
Conclusions
There are a number of ways to provide wide field AO compensation.
• Postprocessing using turbulence profiles• XXAO
At least one of them is likely to work for your observations…