Offner型成像光谱仪前置光学系统设计

针对Offner 型成像光谱仪结构特点，总结了其前置望远系统的选型及设计原则；介绍了一种大视场、长焦距、像方远心离轴三反光学系统的设计方法；利用该方法优化设计了一款焦距800 mm，视场达8.60.148，工作波段0.9~5 m 的星载Offner 型成像光谱仪的前置望远光学系统。对其性能分析表明，在Nyquist 频率16.7 lp/mm 处，各谱段的调制传递函数值均在0.65 以上，接近衍射极限，完全满足成像质量要求。同时证明了该设计方法可行，所设计系统结构紧凑，较易加工，适于空间遥感用Offner 型成像光谱仪。

Design of fore telescope system for Offner imaging spectrometer

In allusion to the specific structural characters of Offner imaging spectrometer, the fundamental design principles of its fore telescope were analyzed. A novel method to design the wide FOV, long focal length and telecentric off-axis three-mirror anastigmatic (TMA) optical system was presented. For the projective demand, a fore telescope system for Offner imaging spectrometer was designed. Its focal length was 800 mm. Its FOV was 8.60.148, and the operation spectrum band was from 0.9 m to 5 m. The evaluation results of its imaging quality demonstrate that the MTF of each spectrum band is higher than 0.65 at the Nyquist frequency 16.7 lp/mm. The imaging quality has reached the diffraction-limitation, which satisfies the pre-designed requirement. Therefore, the design method is feasible. The designed telescope system is compact, easy to be fabricated and suitable for space borne Offner imaging spectrometer.