星载宽波段大气痕量气体临边探测仪光学设计

Optical Design of Spaceborne Broadband Limb Sounder for Detecting Atmospheric Trace Gas

为满足大气痕量气体临边探测的迫切需求,克服传统Czerny-Turner光谱仪由于像散大导致空间分辨率低的缺点,设计了一种可以在宽波段内同时校正像散的改进型Czerny-Turner光谱仪,光谱范围为0.3～0.7μm,全视场角为2.4°,焦距为120mm,相对孔径为1∶6.将离轴抛物面镜与改进型Czerny-Turner光谱仪匹配设计了一个临边探测仪光学系统并运用光学设计软件ZEMAX对临边探测仪光学系统进行了光线追迹和优化并对设计结果进行了分析,结果表明该系统的像散得到充分校正,光学系统在各个谱段的光学传递函数均达到0.69以上,完全满足设计指标要求,也证明了所提出的在宽波段内同时像散校正方法是可行的.

In order to meet the urgent requirements of detecting atmospheric trace gas in limb observation geometry,an optical system of spaceborne broadband limb sounder for detecting atmospheric trace gas is designed.The system is an imaging spectrometer with the working wavelength band from 0.3 μm to 0.7 μm,and its full field of view is 2.4°,focal length is 120 mm,and the relative aperture is 1∶6.To avoid the problems of the classical Czerny-Truner spectrometer,such as low spatial resolution caused by large astigmatism,a modified Czerny-Turner spectrometer is designed,in which astigmatism can be corrected simultaneously in a wide band.By matching the modified Czerny-Turner spectrometer with a off-axis parabolic telescope,an example of limb sounder optical system is designed.Ray tracing,optimization and analysing are performed by ZEMAX software.The analyzed results demonstrate that the astigmatism is substantially corrected,and the MTF for different spectral band is more than 0.69,which satisfies the pre-designed requirement and proves the feasibility of the astigmatism-correction method.