A New Centroid Computation Method Using Dynamic Tracking

Disadvantages of the H S (Hartmann Shack) wavefront sensor in expanding the dynamic range and restraining noise are analyzed. Based on the temporal characteristics of atmosphere turbulence and through determining the scope of change of centroid motion between two adjacent sample periods, a new dynamic track centroid method of H S wavefront sensor is proposed. Using this method, the dynamic range of wavefront sensor can be expanded when atmosphere turbulence is strong. The effect of CCD readout noise and shot noise can be reduced efficiently. The analytical demonstration and simulation results of dynamic centroid computational method are given.