高分辨率空间相机共轴三反光学系统实现形式研究

Coaxial three-mirror-anastigmat system of high-resolution space camera

为了设计出高分辨率空间相机的光学系统,研究了反射式光学系统中存在次镜对主镜的中心遮拦等问题。通过对共轴三反射光学系统结构参数和最终视场在像面上的分布情况的分析,提出了半视场、全视场和环形视场3种光学形式,设计了焦距为3 000 mm、F数为10的3种形式的共轴三反光学系统。设计结果表明:3种共轴三反光学系统在有效视场角内成像质量均接近衍射极限,可以满足高分辨率空间相机不同的使用要求,指出半视场共轴三反光学系统适合于线阵CCD推扫成像,全视场共轴三反光学系统可用于面阵CCD凝视成像,环形视场共轴三反光学系统可实现一台相机上全色和多光谱成像的要求。

The problem that the primary mirror center is obscured by secondary mirror, existing in the reflective optical system, is researched for designing an optical system of the highresolution space camera. Three optical systems of half, full arid annular FOVs were proposed based on the analysis of the structural parameters of the coaxial three-mirror-anastigmat system and the distribution of the final FOV on the image plane. The coaxial three-mirror-anastigmat systems of three modes, whose focal length is 3 000 mm and F number is 10, are designed. The result indicates that the image quality of the three optical systems approaches the diffraction limit in the effective field, and can meet the different demand of high-resolution space camera. It is pointed out that the coaxial three-mirror-anastigmat system with half FOV is suitable to the push-broom imaging of linear array CCD, the coaxial three-mirror-anastigmat system with full FOV can be used to the staring imaging of planar array CCD, and the coaxial three-mirroranastigmat system with annular FOV can realize the full color and muhispectral imaging on a same camera.