空间大气遥感高光谱成像仪光学系统设计

Optical System Design of Multi-Model Hyperspectral Imager for Spaced-Based Atmospheric Remote Sensing

多模式高光谱成像仪已成为空间大气遥感领域的迫切需求,根据多模式空间大气遥感的研究目标,采用扫描系统、离轴抛物面望远系统和双光谱仪级联色散光谱成像系统匹配的结构型式,设计了一个瞬时视场1.8°×0.045°、相对孔径1/2、工作波段250～500nm的星载天底-临边多模式高光谱成像仪光学系统,分成250～330nm和320～500nm两个波段同时探测,利用光学设计软件ZEMAX-EE中进行了光线追迹和优化设计,色散方向不同波长的点列图半径的均方根（RMS）值均小于9.5μm,在250～330nm波段,光谱分辨率为0.17nm,在320～500nm波段,光谱分辨率为0.37nm,均满足小于等于0.6nm的指标要求,高光谱成像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0.9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 multi-model hyperspectral imager. Based on the research objective of multi-model space-based atmospheric remote sensing, an optical system of space-based multi- model hyperspectral imager with nadir and limb models is designed using a scanning system, an off-axis parabolic telescope and a spectral imaging system with a cascade double spectrometer. The instantaneous field of view of hyspectral imager is 1.8°×0.045°, relative-aperture is 1/2, and working waveband is from 250 nm to 500 nm. The waveband from 250 nm to 500 nm is derided two wavebands, one is from 250 nm to 330 nm, the other one is from 320 nm to 500 nm. Ray tracing, optimization are performed by ZEMAX-EE software. The root mean square （RMS） spot radius for different wavelengths are less than 9.5 μm. The spectral resolution is 0.17 nm in the waveband from 250 nm to 330 nm, the spectral resolution is 0.37 nm with waveband from 320 nm to 500 nm, and both of them satisfy the requirement of specification which is less than or equal to 0. 6 nm. The modulation transfer function （MTF） for different wavelengths of hyperspectral imager is more than 0.9 at characteristic frequency in the spatial direction. The design results satisfy the requirements of imaging quality, and is suitable for the application of space- based remote sensing.