Abstract

The compensated field-of-view of a ground-based adaptive-optics system is limited because the phase distortions introduced by atmospheric turbulence vary with the direction of the source. This effect is referred to as anisoplanatism. More specifically, tilt anisoplanatism denotes the differential image motion of two separated point sources observed through a common aperture, while higher-order anisoplanatism refers to variations between the shapes of the two point spread functions. Previous long-exposure observations of a multiple star system [1] have measured the combined effect of these two degradations upon the imaging performance of an adaptive-optics system, but the individual values of these two separate error sources have never been independantly determined. Such measurements would provide a sharper test for theoretical models of anisoplanatic effects, and enable sky coverage calculations for laser guide star adaptive-optics systems to be based upon measured data.

© 1995 Optical Society of America