基于线性渐变滤光片的宽谱段高光谱相机光学系统设计

Optical System Design of Broadband Hyperspectral Cameras Based on Linear Variable Filter

宽谱段高光谱相机能够更为全面地记录目标的光谱信息,是目前高光谱相机所追求的主要方向之一。然而,宽谱段势必会带来系统的色差和二级光谱过大的问题,从而对成像质量造成影响。因此,基于Buchdahl矢量色散分析方法,提出了一种基于线性渐变滤光片的宽谱段高光谱相机光学系统。该系统为一款焦距为100 mm、F数为5、视场角为14.2°且光谱范围在400~1000 nm内的像方远心透射式光学系统。基于该系统的高光谱相机可在500 km轨道处获得空间分辨率为21.5 m、光谱分辨率为10 nm、幅宽为125 km的图像。像质评价及公差分析结果表明,系统具有良好的成像质量并能够满足加工和装调的要求。传递函数测试结果表明,系统符合实际应用需求。

Broadband hyperspectral cameras can comprehensively record the spectral information of a target,which is currently a significant research direction in studies on hyperspectral cameras.However,the broadband is bound to cause problems with excessive chromatic aberration and secondary spectra of the system,affecting the image quality.Therefore,based on an analysis method called the Buchdahl vector dispersion model,an optical system of broadband hyperspectral camera based on linear variable filter is proposed in this study.An image side telecentric transmitted optical system with a focal length of 100 mm,Fnumber of 5,field of view of 14.2°,and spectral range of 400‒1000 nm was designed.The hyperspectral camera based on this system can capture images with a spatial resolution of 21.5 m,spectral resolution of 10 nm,and swath width of 125 km at an altitude of 500 km.The image quality evaluation and tolerance analysis show that the system has an excellent image quality and satisfies fabrication and alignment requirements.The modulation transfer function test results show that the system can satisfy actual application requirements.