Interferogram stitching method in measuring the form deviation of curved surface with laser interferometry

When the form deviation of curved surface is measured with oblique laser interferometry, the dense fringes are almost inevitable and prevent a high processing accuracy. This paper focuses on a stitching method to solve the problem: firstly, the reliable area in interferogram is evaluated according to the fringe width. Secondly, all interferograms are positioned on the measured surface which is regarded as the stitching reference. Thirdly, the transform models of different interferograms are estimated based on the same center of optical axis. Fourthly, the form deviations from different reliability areas are resampled. The experimental results are given to verify the feasibility.