机载高光通量双波段成像光谱仪的设计

分析了成像光谱仪常见结构的优缺点并给出了分析过程,对望远镜系统和光谱成像系统结构进行了合理选择,实现了单一成像光谱仪同时覆盖可见近红外(VNIR)和中波红外(MWIR)双波段。根据研究目标要求设计了一个大F数(VNIR波段F/3,MWIR波段F/2)机载双波段成像光谱仪。该光谱仪双通道共用一个同轴平场无遮挡Schwarzschild望远镜,用二向色分束器分开。双通道光谱成像系统均采用同心共轴的Dyson结构,VNIR波段和MWIR波段光谱分辨率分别达到5 nm和15 nm。为使设计的系统结构合理,介绍了光束分离结构和光谱仪的光束折叠方法。设计结果表明:该系统结构简单,效果良好,谱线弯曲分别小于1.2μm和0.5μm,谱带弯曲均小于0.5μm,偏振灵敏度小于4%,适用高光谱分辨率机载双波段成像光谱仪。

Optical design of an airborne dual-wavelength imaging spectrometer with high throughput

Advantages and disadvantages of some common structures of imaging spectrometer were analyzed and the process was given.Some selection of optimum configurations for telescope and spectrometer was proceeded.A single imaging spectrometer covering visible near infrared(VNIR) band and medium wave infrared(MWIR) band simultaneously was presented.An optical design of a fast(F/3 for VNIR and F/2 for MWIR) airborne dual-wavelength imaging spectrometer was presented based on the research objective,of which the two channels shared a common flat-image unobscured Schwarzschild telescope with common axis and separated by a dichroic beam splitter.Both the spectrometers utilized concentric Dyson structure with a common axis and achieved 5 nm and 15 nm spectral resolution respectively.For obtaining a rational designing structure,beam splitting structure and beam folding structure were discussed.The design results show that an excellent performance is obtained despite the simple structure,the smile are less than 1.2 μm and 0.5 μm,and both the keystone are less than 0.5 μm,respectively,and the polarization sensitivity is less than 4%.It can be used as an airborne dual-band imaging spectrometer with high spatial resolution.