双狭缝高分辨率紫外成像光谱仪光学系统设计

Design of Hyperspectral Resolution Ultraviolet Double-Slit Spectrometer System

摘要:

在机载和星载领域,尤其是用于观测科学目标短期变化的应用领域,遥感平台逐步要求光谱仪在实现高分辨率的同时缩短重访时间。研究了基于Offner结构的紫外成像光谱系统,设计了一种工作波段为250~500nm、双狭缝均长50mm、双入射狭缝间隔为37mm、光谱分辨率为0.3nm的双缝高分辨率紫外成像光谱仪,并对设计结果进行了分析与评价。结果表明,这种紫外双缝成像光谱仪在41.67lp·mm-1处的传递函数达到0.76以上,实现接近衍射极限的优良成像质量,同时大大缩短了系统重访时间,提高了系统的信噪比,在保证高分辨率的同时缩小了系统体积和扫描镜口径,适合机载和星载遥感应用。

Abstract:

In the fields of airborne and satellite-borne, especially for the observation of short-term changes in scientific objectives, remote sensing platforms are increasingly requiring spectrometers to reduce revisit time while achieving high resolution. Based on Offner grating dispersive imaging spectral system, a kind of high-resolution ultraviolet double-slit spectrometer was designed the working wavelength of 250~500nm, each slit length of 50mm, the interval between slits of 37mm and the spectral resolution of 0.3nm. Design and analysis results show that, for this kind of configuration of the double-slit spectrometer, the MTF is more than 0.76 for various wavelengthes and different fields of view, and more than 90% of the encircled energy for centric and edge wavelengths is within one pixel. This kind of configuration has excellent imaging quality close to diffraction limit. Meanwhile, the configuration reduces the system’s revisit time, improves the system’s SNR and ensures the high resolution while reducing the system size and scanning aperture, which is suitable for airborne and satellite-borne remote sensing applications.