多角度偏振成像光谱仪的光学设计

Optical design of multi-angle imaging spectropolarimeter

大气气溶胶是引起全球气候变化和空气质量问题的重要因素之一,利用卫星遥感监测全球大气气溶胶具有重要意义。利用大气气溶胶的多角度偏振光谱信息联合反演,可有效去除地表反射的影响,获得精确的遥感结果,因此亟需研究具备多角度偏振光谱信息获取能力的一体化光学仪器。所设计的多角度偏振成像光谱仪光学系统,前置望远物镜采用多镜头视场拼接方式,实现地面目标沿轨方向±60°内多角度探测,分光系统共用一个Offner分光装架。像质评价结果显示,在探测器奈奎斯特频率处中心波段的MTF达到0.8,点列图均位于艾里斑范围内,各项指标均满足设计要求。光学系统整体结构紧凑、无运动部件,可实现目标多角度偏振光谱图像的信息获取。

The atmospheric aerosol is one of the most important factors leading to the global climate change and air quality problems, it is very meaningful to detect the global atmospheric aerosol by satellite. By the joint retrieval of the multi-angle spectral polarimetric information of atmospheric aerosol,the influences of earth surface reflection can be elimated and the accurate detecting outcome is gotten.Thus it is quite urgent to study the integrated optical instrument with the ability to detect multi-angle spectral-polarimetric information of target. The optical system of multi-angle imaging spectropolarimeter was designed, the fore telescope was composed of multi mini-lens, which realized the multi-angle detecting in range of ±60° along the orbit. The spectroscope system was a common Offner imaging spectrometer. The analysis of imaging quality shows that the MTF of middle waveband at Nyquist frequency is higher than 0.8, and the spot diagrams are all smaller than the Airy disk. All indexes satisfy the commands of system. This optical system is compact in size without any moving part, and can realize the detection of multi-angle polarization state, spectral information and intensity of target.