Large-aperture mirror test using sparse sub-aperture sampling

Due to the low efficiency of testing large-aperture mirrors in the polishing process by sub-aperture stitching technology, the sparse sub-aperture sampling technology was put forward and analyzed. Full aperture maps gained by different sparse sub-aperture sampling and the actual full aperture map were compared. The sparse sub-aperture sampling with a reasonable distribution may achieve the same accuracy as the full aperture test does. Thus the sparse sub-aperture sampling technology could be used in the polishing process to improve test efficiency.