Abstract

A seemingly obvious way to circumvent the focus anisoplanatism d₀-limitation on a useful aperture diameter that goes with use of a (single) guide star spot is to use a multiplicity of relatively closely spaced spots, using the wavefront distortion data from each only for the portion of the aperture directly below that spot, and to stitch these patches of data together to form a wavefront distortion estimate that covers the full aperture. We present results for the mean-squares wavefront error, E², that go with guide star spot patterns of (1) a dense array of spots at a single altitude, (2) dense arrays of spots at two altitudes, and (3) an equilateral triangle pattern of three spots at a single altitude. In all cases we find that we can write E² = (D/d₀)^5/3. Expressions have been developed for d₀ for all cases. A key feature in the development of these results is the incorporation of the effect of our not being able to determine exactly where each of the guide star spots really is.

© 1991 Optical Society of America