Adaptive Cross-Correlation Algorithm and Experiment of Extended Scene Shack-Hartmann Wavefront Sensing

摘要

We have developed a new, adaptive cross-correlation (ACC) algorithm to estimate with high accuracy the shift as large as several pixels in two extended-scene images captured by a Shack-Hartmann wavefront sensor (SH-WFS). It determines the positions of all extended-scene image cells relative to a reference cell using an FFT-based iterative image-shifting algorithm. It works with both point-source spot images as well as extended scene images. We have also set up a testbed for extended-scene SH-WFS, and tested the ACC algorithm with the measured data of both point-source and extended-scene images. In this paper we describe our algorithm and present our experimental results.