Lateral Location Error Compensation Algorithm for Measuring Aspheric Surfaces by Sub-aperture Stitching Interferometry

摘要

Sub-aperture stitching (SAS) testing method is an effective way to extend the lateral and vertical dynamic range of a conventional interferometer. However, the center of each sub-aperture could be in error because of the complex motion of the mechanical platform. To eliminate the affection of lateral location error in the final stitching result, a lateral location error compensation algorithm is introduced and the ability of the algorithm to compensate the lateral location error is analyzed. Finally, a 152.4mm concave parabolic mirror is tested using SAS method with the compensation algorithm. The result showed that the algorithm can effectively compensate the lateral location error caused by the mechanical motion. The proposal of the algorithm can reduce high requirement of mechanical platform, which provides a feasible method for the practical application of the engineering.