星地激光通信中地球背景辐射的抑制研究

研究了星地激光通信中地球背景辐射及其抑制技术。推导出了不同轨道处星上终端的地球背景辐射入瞳功率理论公式，提出了固有杂散辐射的概念，并对其作了理论推导。针对一个典型的终端对其地球背景辐射进行了理论计算，并设计了不同形式的遮光系统。最后利用光学仿真软件 LightTools 对不同轨道高度、不同遮光系统形式的星上终端的杂散辐射进行了仿真，得到了轨道高度以及遮光系统形式对杂散辐射的影响曲线，并对其作了分析。为星地激光通信中星上终端的地球背景辐射提供了理论依据，为星上终端的遮光系统设计提供了仿真依据。

Decreasing earth background radiation in satellite-ground communication

The earth background radiation and its suppression technologies for satellite-ground laser communication system were studied. Firstly, a theoretical formula of the power of entrance pupil caused by earth background radiation at different orbits was derived, and the concept of inherent stray radiation was put forward and theoretically deduced. Furthermore, theoretical calculations of earth background radiation for a typical terminal were accomplished, and baffle system designs of different forms were given. Finally, optical simulation software LightTools was used to simulate the stray radiation of the terminal with different forms of baffle system at different orbits, and then the curves of stray radiation affected by orbit altitude and the form of baffle system were obtained and analyzed. This article provides a theoretical foundation of earth background radiation for the satellite-ground laser communication and a simulation basis for baffle system of the laser communication terminal on the satellite.