大视场高分辨力星载成像光谱仪光学系统设计

Optical System Design of Wide-Angle and High-Resolution Spaceborne Imaging Spectrometer

大视场、高分辨力星载成像光谱仪已成为空间遥感的迫切需求。根据大视场、高分辨力的研究目标,提出了先视场分离分光再用分色片分光的设计方法,分析了视场分离分光的原理。设计了一个全反射式星载成像光谱仪光学系统,该系统由指向镜、11.42°远心离轴三反消像散(TMA)前置望远系统和4个Offner凸面光栅光谱成像系统组成,通过恰当选择4个光谱成像系统的变倍比来实现2种探测器的匹配。运用光学设计软件CODE V对成像光谱仪调制系统进行了光线追迹和优化,并对设计结果进行了分析。分析结果表明,光学系统在各个谱段的光学传递函数均达到0.7以上,完全满足设计指标要求;同时证明了设计方法是可行的。

Space remote sensing urgently requires wide-angle and high-resolution spaceborne imaging spectrometer. According to the research objective of wide angle and high resolution, the design method of firstly dividing field of view （FOV） and secondly dividing beam using dichroscope is developed. The principle of dividing FOV is analyzed. A reflective spaceborne imaging spectrometer is designed, which is composed of a pointing mirror, a 11.42° telecentric off-axis three-mirror anastigmatic （TMA） telescope and four Offner convex grating spectral imaging systems. The proper magnification is chosen for each spectral imaging system to match two types of detectors. Ray tracing and optimization are performed and analyzed by CODE V software. The results demonstrate that the modulation transfer function （MTF） for different spectral bands is more than 0.7, which satisfies the pre-designed requirement. The design method is proved to be feasible.