A Computationally Efficient Method for Wavefront Reconstruction

A fast algorithm for measuring Hartmann spot positions is combined with a computationally efficient reconstructor running on a pair of i860XP processors to achieve 1000 reconstructions per second. The full-featured reconstructor removes unobservable modes, as well as tilt which is handed to a steering min or with high dynamic range. Moreover, the reconstructor can perform much of its processing on the fly while the frame is being transferred from the pupil plane camera, resulting in significantly reduced servo phase lag. Details of the fast reconstructor are described with particular emphasis on the creative use of computational resources.