基于曲面棱镜的宽视场推帚式高光谱成像仪设计

A Wide-Field Push-Broom Hyperspectral Imager Based on Curved Prism

设计了一种覆盖短波红外谱段的宽视场推帚式高光谱成像系统,可用于空间遥感平台搭载获取高光谱数据立方体,分析地表物质组成及其理化特性。采用曲面棱镜作为色散元件,它集色散和成像功能于一体,通过与Offner中继结构相结合,大大简化了光谱仪光学系统的设计。相比传统色散型光谱成像仪,其结构紧凑、体积小、重量轻,而且能够有效校正棱镜色散带来的谱线弯曲和色畸变的问题。相比同类型的基于Offner中继结构的光栅光谱成像仪,其能量利用率高。分析了曲面棱镜的近轴光学理论和Offner中继结构的成像特点,给出了光谱仪的设计指标和结果,并对其光谱成像质量进行了评价。

A wide-field pushbroom hyperspectral imager covering short-wavelength infrared range is presented,which can be carried by space borne or airborne platform for remote sensing,acquiring hyperspectral data cube,and analyzing substance compositions and physicochemical properties.Curved prism which simultaneously possesses the functions of dispersion and imaging is used as the prismatic element,and the combination with Offner relay configuration substantially simplifies the design of spectrometer.Compared to conventional dispersive spectral imagers,this design is compact,light-weighted,and small-sized,and can efficiently correct unavoidable spectral line curve（smile） and spectral band（keystone or frown） by prismatic dispersion.Compared to grating spectral imagers of the same configuration,the energy utilization efficiency of this design is much higher.The paraxial aberration theory and imaging characteristics of Offner relay configuration is briefly described.The optical layout and image evaluations,including spatial and spectral dimensions,are illustrated respectively,according to Monte Carlo ray-tracing results of seven principal wavelengths.