由于现有评价与测试方法不能满足3～4 m地基光电探测系统在不同仰角下对光学系统波前检测的需求, 本文提出了基于子孔径斜率离散采样, 再重构全口径波面轮廓的波像差测试方法。采用光学模拟与数学分析协同仿真的方法, 研究了波面重构算法的不确定度以及扫描运动引起的子孔径倾斜误差、子孔径扫描位置误差、像点坐标测量误差与波前复原精度间的作用规律。仿真结果显示, 迭代算法的相对误差ΔPV为0.002 8λ(λ=632.8 nm), 模式算法的相对误差ΔPV为0.002 7λ。当子孔径倾斜误差小于0.2″, 波面重构误差ΔPV约为0.02λ。当子孔径采样位置精度优于0.2 mm, 其引入的波面重构误差小于0.04 nm(PV); 当子孔径像点坐标提取精度优于5 μm, 波面重构误差ΔPV约为0.03λ。研究结果表明, 当考虑波面重构过程中的实际测量误差时, 模式算法的误差容限较高, 收敛性更好。此外, 构建实际测试装置时, 需引入角度监测与算法误差补偿机制, 子孔径倾斜角度监测系统的测角精度需优于0.2″。

Existing evaluation and testing methods are difficult to apply to the wavefront aberration test at different elevation angles for a photoelectric telescope with 3—4 m aperture. Therefore, this paper presents a Wavefront Error(WFE) test method by subaperture wavefront slope discrete sampling and then reconstructing the full aperture wavefront aberration. On the basis of the co-simulation by mathematical analysis and optical simulation, it studies the relationship between wavefront reconstruct accuracy and sub-aperture scanning motioned tilt error, sub-aperture scanning position tilt error, image point coordinate measuring error and wavefront reconstruction algorithm uncertainty. Collaborative simulation results show that the relative error(ΔPV) of iterative algorithm is about -0.002 8λ (λ=632.8 nm), and the relative error(ΔPV) of pattern algorithm is -0.002 7λ. When the sub-aperture tilt error is less than 0.2″, the wavefront reconstruction error(ΔPV) is about 0.02λ. When the sub-sampling aperture position error is less than 0.2 mm, the wavefront reconstruction error(PV) introduced is less than 0.04 nm. And when position error of imaging point is less than 5 μm, the wavefront reconstruction error (ΔPV) introduced is less than 0.03λ.The results demonstrate that the pattern algorithm has a higher error margin, and the convergence is better when the measurement errors are considered. Moreover, it suggests that it should take the angle monitoring and error compensation mechanisms into account and the angle measuring accuracy of the sub-aperture tilt monitoring system should be better than 0.2″when an actual measuring equipment is established.