子孔径拼接干涉测量的精度估计方法

作为一种高精度的光学镜面测量方法,子孔径拼接干涉测量的精度指标十分重要,必须对其进行定量估计.提出将子孔径拼接十涉的结果与全口径测试结果进行对比实验,将全口径测试结果作为拼接测量结果的参考真值,讨论了拼接测量精度评价指标及其计算方法.全口径测试与子孔径拼接干涉测量的几何参量并不相同,提出将全口径测试结果与子孔径拼接结果进行最优匹配,其原理与子孔径拼接算法的原理相同.在最优匹配后计算拼接测量精度的评价指标,通过测量实验进行了验证,结果表明最优匹配后的误差指标比未经最优匹配的误差指标减小约48%,证明上述方法是一种定量估计子孔径拼接干涉测量精度的有效方法.

Approach to Accuracy Evaluation for Subaperture Stitching Interferometry

As a high-precision testing method for optical surfaces, accuracy of the subaperture stitching interferometry is very important and must be evaluated quantitatively. The contrast test approach is proposed to evaluate the measurement accuracy with the full aperture test taken as a reference. Then the figures of merit as well as their computing methods are discussed. Since the geometrical parameters are different in the full aperture test and the subaperture stitching test, optimal matching is proposed between the two test results. The principle resembles that of the subaperture stitching algorithm. The figures of merit are computed following the matching process. Finally experiments are presented, and the results show the figure of merit with matching is reduced by about 48% of that without matching, which proves the validity of the approach for quantitative accuracy evaluation of subaperture stitching interferometry.