大口径抛物面镜子孔径拼接测量

Sub-aperture stitching interferometry for large parabolic mirror

针对大口径抛物面面形检测,提出一种基于无像差点的子孔径拼接测量新方法。首先,分析了该拼接方案特殊的子孔径生成方式及子孔径名义运动路径计算的形式;其次,通过建立统一的像面坐标系和全局坐标系的函数关系,结合坐标转换求解出各个子孔径数据对应的全局坐标;最后,采用目标函数法拼接恢复出全口径面形。对一抛物面镜利用该拼接方案进行了计算机仿真实验,拼接得到RMS值的偏差为0.001 4λ。实验结果表明,该检测方法可以实现大口径抛物面镜的高精度测量。

Based on research of surface measurement method for large-diameter parabolic mirror, a new sub-aperture stitching measurement technology based on aberrationless theory was proposed. Firstly, the special method of sub-apertures′ generation and the calculation form for sub-apertures′ nominal motion path of this stitching program were analyzed. Secondly, a unified function between image plane coordinate system and the global coordinate system was established, together with coordinate transformation, the global coordinate of each sub-aperture data was solved. Finally, the full aperture surface was recovered by the objective function method. The simulation experiment was established for parabolic mirror, the stitching deviation of RMS is 0.001 4λ. The experimental results show that this measurement method can achieve high precision measurement for large-diameter parabolic mirror.