星光折射自主导航星敏感器及光学系统设计研究

Research on the Autonomous Star Sensor Based on Indirectly Sensing Horizon and its Optical Design

基于星光折射间接敏感地平自主导航星敏感器的工作原理,详细分析了星光折射星敏感器的探测参数设计,包括探测谱段、恒星观测视场、探测概率及阈值星等、恒星探测能力等。星光折射星敏感器的观测视场分为折射星与非折射星两部分,对折射星的观测视场随轨道高度增加而减小;受限于大气光谱吸收,观测折射星的谱段宜选择600~900 nm,探测信噪比随大气折射高度降低而减小。采用高灵敏度的背薄电荷耦合器件（CCD）以及精度达到微米级的无热化光学系统匹配设计。结果表明,光学系统像质良好,单一星敏感器单星测量精度达到1″,满足目前航天自主导航对姿态及位置测量精度的需求。

Based on stellar refraction indirectly sensing of autonomous navigation for horizon star sensor, a parameter design is analyzed for stellar refraction star sensor which is included by detect waveband, observation field, detect probability and threshold value of magnitude. The field of view （FOV） of star sensor is divided into two parts of refraction star and unrefraction star. The FOV decreases as orbit attitude increases. Limited by atmosphere absorption, the waveband needs to be 600-900 nm, and the signal-to-noise ratio （SNR） decreases as atmosphere height increases. High sensitive back-thinned charge coupled device （CCD） is applied and athermalizing optical system design is achieved. The result shows that imaging quality is good enough and measure precision of single star sensor achieves 1＂, which can meet the requirement of autonomous star sensor measure precision.