最大似然估计法去除子孔径拼接检测中的支撑误差

Maximum Likelihood Estimation Method to Eliminate Supporting Error in Subaperture Stitching Interferometry

为了去除拼接干涉检测中支撑对面形检测的影响,提出了利用最大似然估计法计算支撑造成的面形误差的方法。首先,保持支撑工装不动,旋转待测镜检测各子孔径面形;然后,用最大似然估计法计算出支撑造成的面形误差;最后,各子孔径面形数据减去估算出的支撑面形误差,利用拼接算法拼接出全口径面形。以全口径直接测量结果为基准进行对比实验,验证了该方法可去除支撑造成的面形误差,提高了拼接检测精度。

In order to eliminate the measurement error caused by the support of the subaperture stitching interferometry, the method of maximum likelihood estimation is proposed to calculate the deformation due to the support. The first step is to maintain the brace immobility, rotating the test lens to measure the subaperture surface. Then, the maximum likelihood estimation method is used to calculate the deformation caused by the support. Finally, the interferometer measurement data of the subaperture surfaces subtract the estimated support surface error, and the stitching algorithm is used to splice a full aperture surface shape. The experiment results are compared with the result of the full aperture direct interferometer measurement, which shows that the method can remove the deformation caused by the support and improve the accuracy of the stitching detection.