Optical System Design Of High-resolution Micro Remote Sensing Video Camera

Video satellite with fast and agile maneuverability can monitor dynamic target real-time, which makes rapid adjustment and change according to actual situatio n observed in the region. So there is a broad application prospect in the field of military and civilian. O ne class of low orbit micro video satellites which utilizes agility of the platform to realize staring observation is arousing more and more attentio n. For adaption of small satellite platform with low cost, it is urgent to design and develop compact long focal length optical system with not only small volume, light weight, easy implementation, but also with two-dimensional field.First, this thesis expounds the working principal of remote sensing video camera which is based on researches at home and abroad. Depending on the application of requirements, some indicators of optical system such as effective focal length, field of view and relative aperture are analyzed and determined, and also the initial structure is selected. Then, design idea is introduced and design schemes of two- mirror catadioptric system and coaxial three- mirror system are emphasized research. By deriving the condition of eliminating secondary obscuration and the relation between optical total length and the tertiary relay magnification of full- field coaxial three-mirror system, reasonable selection range of the tertiary relay magnification is described. With combination of primary aberration theory, methods are given to determine initial structural parameters. Optimized optical system is satisfied with performance requirements and image quality, which is of small aspherical surface, easy alignment and no need of bulky outer baffle. Comparing optical total length, obscuration coefficient, distortion and number of aspherical surface of above two designs, comprehensive performance of coaxial three- mirror system is better than two-mirror catadioptric system. Finally, tolerances, thermal aberration, stray light and optical detection path of three aspherical mirrors of coaxial three- mirror system are analyzed and optimized which lays a foundation for the next research work.