Turbulence-induced adaptive-optics performance degradation: evaluation in the time domain

Abstract

A time-domain approach has been developed that is capable of evaluating the performance of an adaptive-optics system degraded by a wide variety of effects acting together or alone. In the study conducted here the normalized antenna gain (or Strehl ratio) is evaluated for a system degraded by turbulence, anisoplanatism, a finite servo bandwidth, and a combination of anisoplanatism and a finite servo bandwidth. A diameter dependence of these effects is established, illustrating that the degrading influence associated with a finite servo bandwidth is less severe than the degrading influence associated with anisoplanatism over a wide range of diameters. For the case of a small-diameter system degraded by anisoplanatism, system performance improves slightly when a finite servo bandwidth is introduced.