为了减小非球面环形子孔径拼接测量时的中心偏移误差, 根据检测原理及几何关系, 分析了中心偏移误差在面形测量中的作用机理, 推导了中心偏移误差模型, 并在此基础上提出了一种基于二维像素矩阵的中心偏移误差补偿方法.该方法可以有效地得到初始面形测量数据的中心偏移量, 在拼接之前减小由中心偏移误差引起的波前偏差的剔除误差, 同时减小各环形子孔径中心之间的偏差.利用Zygo干涉仪进行了非球面环形子孔径拼接的中心偏移误差补偿实验, 与零位检测结果相比, 峰谷值残差为－0.015λ, 均方根残差为0.003λ, 表明该补偿方法大大减小了面形测量误差, 提高了环形子孔径拼接的测量精度.

In order to reduce the center offset error in aspheric surface testing by annular subaperture stitching interferometry, the mechanism of action of center deviation error in the surface shape measurement was analyzed, and the error model based on the testing principle and geometrical relationship was established. A compensation method for the center offset error based on two-dimensional matrices of pixel was proposed. The method is effective for searching the center offset of the initial surface shape measurement data and reducing the eliminate error of the wavefront error caused by the center offset error, and the error among the centers of annular subapertures can also be decreased. The error compensation experiment for the annular subaperture stitching interferometry was carried out with Zygo interferometer. The errors of peak to valley value and root mean square are －0.015λ and 0.003λ respectively compared with the null aspheric surface testing result. The experiment results show that the proposed method greatly reduces the surface measurement errors and improves the measurement precision of annular subaperture stitching interferometry.