Optical System Compact Design And Stray Light Analysis Of Micro/Nano Satellite Remote Sensing Camera

With the widespread application of aerospace technology and the rapid development of micro/nano satellite technology,the demand for high-resolution Earth's surface image data around the world has increased significantly.High-performance micro / nano satellites are increasingly valued due to their high efficiency and good cost performance,especially in the field of optical remote sensing.The development of high-performance compact optical loads which suitable for micro/nano satellites becoming one of the most critical research topics around the world.This paper explores the feasibility of the compact design of optical remote-sensing cameras,in order to fit the narrow space in micro/nano satellites.This articles contains the following four aspects:1)The development of high-performance micro/nano satellites both in China and abroad is introduced,the working mode and mechanism of the micro/nano satellite remote sensing camera are explained,and the basic structure of optical system has been determined according to the relevant indicators which are calculated in this paper.2)Focusing on the compactness of the catadioptric optical system,a negative focal power correction lens group is used in the optical system,and a Mangin mirror is introduced to compactify the optical system.The primary aberration theory of Mangin mirror was summarized.The introduction of a Mangin mirror shorten the tube length of the optical system,which meets the compact design idea of the optical system.3)In the light of the compactness of the coaxial three-mirror optical system,for the first time,a folding axis three-reflection type folding axis mirror is integrated with the secondary mirror body,the primary mirror and tertiary mirror are integrated,and an initial structure calculation method of the optical system is proposed.Design optimization ?the result of tolerance analysis and experiments are given.This design opens up new ideas for lightweight and simplicity of optical systems.4)Proposing the stray light analysis of the compact three-mirror optical system.The stray light analysis model was established for the optical system,and the outer lens hood and light blocking ring of the primary mirror were calculated and designed.The shutter-type hood was designed to avoid the stray light incident at a small angle and its influence on the blocking ratio of the optical system was analyzed.By calculating the corresponding PST values at different angles before the system changing and the after,the rationality and feasibility of the de-lighting structure are verified.