Effect Modelling and Simulation of Earth Stray Light on Space-Born Telescope

摘要

Space-born telescope is an important means to detect space dim objects, however, earth stray light outside FOV will reach its image plane when the camera is working, bringing the noise and creating a background. The lighted earth is a nonuniform spherical reflecting source and the amount of contamination depends on location of the sun and the satellite, sensor pointing, FOV, PST of the telescope design and so on. In order to provide reliable analysis results for bringing out the reasonable stray light mitigation scheme, quantificational modelling and simulation is needed. Firstly the characteristics of earth stray light was analysed, and base on the complex characteristics of stray light contamination, a mathematical model combined with time and space was built in this paper. Secondly, the mathematical models were translated to simulation codes, realizing effects simulation for different conditions. At last, taking a space based visible as an example, effects at different states were analysed.