星载宽视场差分吸收成像光谱仪光学设计

Optical Design of Space-Based Wide Field-of-View Differential Optical Absorption Imaging Spectrometer

研究星载宽视场差分吸收成像光谱仪已成为空间大气遥感领域的迫切需求,根据宽覆盖轻小型星载大气痕量气体差分吸收成像光谱仪的研究目标,采用偏轴两镜系统和中继系统匹配的结构型式设计出无遮拦宽视场望远系统,将宽视场望远系统和Offner光谱成像系统匹配,设计了一个视场60°×0.24°、相对孔径1/3、工作波段280～450 nm的星载宽视场差分吸收成像光谱仪光学系统,利用光学设计软件Zemax-EE进行了光线追迹和优化设计,光谱成像系统不同波长的点列图半径的均方根（RMS）值均小于5 mm,光谱分辨率0.692 nm,满足不大于1 nm的指标要求,差分吸收成像光谱仪全系统在空间方向各波长在特征频率处的光学传递函数均达到0.67以上,完全满足成像质量要求,适合空间大气遥感应用。

Space-based atmospheric remote sensing urgently requires wide field-of-view differential optical absorption imaging spectrometer. The research objective is spaced- based atmospheric trace gas differential optical absorption imaging spectrometer with wide covering range and minor volume and mass. Based on the research objective, a wide field-of-view unabscured telecope is designed using an off-axis two-mirror system and a relay system. An optical system of space- based wide field- of- view differential optical abdorption imaging spectrometer is designed using the wide field- of- view telescope and an Offner spectral imaging system. The field of view of hyspectral imager is 60°×0.24°, relative-aperture is 1/3, and working waveband is from 280 nm to 450 nm. Ray tracing and optimization are performed by Zemax- EE software. The root mean square（RMS） spot radius for different wavelengths are less than 5 mm for the Offner spectral imaging system.The spectral resolution is 0.692 nm, and the requirement of specification is no more than 1 nm. The modulation transfer function（MTF） for different wavelengths of imaging spectrometer is more than 0.67 at characteristic frequency in the spatial direction. The design results satisfy the requirements of imaging quality, and are suitable for the application of space-based remote sensing.