分块式空间望远镜的波前校正方法

A Wavefront Correction Method for a Segmented Space Telescope

对于同时具有可变形分块式主镜和变形镜的空间望远镜光学系统,提出一种基于小波分解的并联波前校正法。该方法根据分块式主镜和变形镜的空间校正能力不同,利用小波分析的多分辨率分析的特点按不同尺度分解波前误差,将空间频率高于主镜空间带宽的各层波前误差合并为高频波前误差由变形镜校正,余下的低频误差由主镜校正;应用MATLAB小波工具箱对并联波前校正法进行数学仿真,并与依光路顺序的串联波前校正法进行比较,结果说明基于小波解耦的并联校正法波前校正精度高于串联校正法,适用于空间望远镜光学系统。

For the space-based telescope with a large segmented primary mirror and a deformable mirror, a new parallel wavefront correction method based on wavelet decomposition was presented. Because of the different corrective capability,wavefront error was decomposed in the different measures using wavelet multi-resolution analysis. Then the wavefront errors with high spatial frequency which was above the influence function spatial bandwidth of primary mirror were corrected by the deformable mirror,and residual low spatial frequency wavefront errors were corrected by primary mirror. The parallel wavefront correction method was simulated using wavelet toolbox of MATLAB and compared with series wavefront correction method according to the optical path. Results show the parallel method has better wavefront correction precision than the series method,and it is applicable for the space-based telescope optical system.