National Optical Astronomy Observatories (NOAO) Infrared Adaptive Optics Program II: Modeling Atmospheric Effects In Adaptive Optics Systems For Astronomical Telescopes

Abstract

However pertect an adaptive optical system can he, it win never tuiiy correct tne image. We discuss here the effects of amplitude errors due to stellar scintillation, the effects of chromatic errors due to both refraction and diffraction in a two-wavelength system, and the effects of non-isoplanicity. All these errors are directly related to the height of turbulence layers. An expression is derived for the scale height of turbulence which should be considered as an important parameter in selecting new sites for astronomica observations. The performances of adaptive optical systems are usually described in terms of Strehl ratios. We present here the results of computations of the whole transfer function for lon exposure compensated images. It is shown that the point-spread function for a partially compensated image generally consists of an Airy disk surrounded with a halo. The ratio of the energy in the Airy disk over the energy in the halo is independent of the telescope aperture and provides a better measure of the quality of the compensation.