GLOBAL WAVE-FRONT RECONSTRUCTION USING SHACK-HARTMANN SENSORS

A method is proposed for deriving the form of a turbulence-distorted wave front from Shack-Hartmann data by modeling the polychromatic imaging process in detail. In this way a higher order of reconstruction is possible than by methods that use only the barycenters (centers of gravity) of the individual spots. Simulations are presented showing the possible gains for a range of conditions of turbulence and photon flux. When photon noise is negligible the residual phase errors are approximately three times smaller than what is achievable by use of only the barycenters. The choice of functions for representing wave-front distortions is also considered with regard to the quality of the reconstruction obtained and to numerical efficiency.