星载大视场多光谱成像光学系统设计

大视场、多通道、小型化已成为星载测绘光学系统的迫切需求。根据上述需求，提出了先用视场分光再用窄带分色片分光的设计方案、并构建了自动消遮挡和轻小型化优化函数。设计了一款主、次、三镜均为球面的离轴三反四通道光学系统，其焦距360 mm、相对孔径为1/6、视场角13°×5°、工作波段0.4~1.1 m、地面像元分辨率5 m、全视场畸变小于5%。加工、装调后的整机系统实测MTF（Modulation Transfer Function）曲线在奈奎斯特频率100 lp/mm处均大于0.25，同时系统所占空间面积仅为245 mm×423 mm、整机重量仅13.82 kg，从而实现了系统大视场、无遮挡、多通道、体积包络的小型化。

Design of Spaceborne Large Field of View Multispectral Imaging Optical System

A large field of view, multi-channel, lightness, and miniaturization have all become critical requirements for satellite-borne surveying and mapping optical systems. According to the above-mentioned requirements, a design method that uses the field of view to split light and then uses a narrowband dichroic plate to split light is proposed, and an optimization function for automatic de-occlusion, lightness, and miniaturization is constructed. This method was used to design an off-axis three-mirror four-channel optical system with spherical primary, secondary, and tertiary mirrors. For the ground image, the focal length was360mm, relative aperture was 1/6, field of view was 13°×5°, and working waveband was 0.4– 1.1m. The element resolution was 5 m, and the distortion of the full field of view was less than 5%. The entire system installation and adjustment were completed according to the tolerance analysis results. After processing and installation, the measured modulation transfer function (MTF) curve of the100 lp/mm entire system was greater than 0.25. The system had good image quality and it occupied only 245 mm×423 mm and the entire weight was only 13.82 kg. This shows that the system had excellent characteristics of a large field of view, no obstruction, lightness, and miniaturization.