Nonlinear estimation of misalignment errors in adaptive optics

The performance of adaptive optics systems degrades rapidly in the presence of optical misalignment errors between deformable mirror and wavefront sensor. In order to compensate for this effect, it is necessary to estimate the misalignment error. In this paper, we present a model for misregistration estimation, and a nonlinear estimation algorithm for generating globally optimal estimates of misregistration errors. The performance of the algorithm is illustrated using an experimental adaptive optics system.