Maximum Likelihood Estimation of Wave Front Slopes Using a Hartmann-Type Sensor

摘要

Current methods for estimating the wave front slope at the pupil of a telescopeequiped with a Hartmann type wave front sensor (H-WFS) are based on a simple centroid calculation of the intensity distributions (spots) recorded in each subaperture of the H-WFS. This thesis devises a maximum likelihood (ML) estimation of the spot centroids by incorporating statistical knowledge of the spot shifts. The light level in each subaperture and the relative spot size is also employed by the shift estimator. The shift estimator is found to be unbiased and is upper bounded by the mean squared error performance exhibited by the classical centroid technique.