环境温度对星敏感器测量精度有一定影响。运用光机结合方法,研究环境温度对星敏感器测量精度的影响。在计算典型星敏感器光学系统热效应引起的结构参数变化的基础上,分析了星敏感器星点定位误差。计算结果表明:在视场角0°附近,环境温度变化对星点定位精度影响较小;通过材料匹配,减小系统温度焦移系数,可以减小环境温度变化引起的星点定位误差。热补偿设计后,在环境温度-20～60℃范围内,星敏感器最大测量误差仅为0.02″,约为原系统的1/7。

Measurement accuracy of star sensor is restricted by ambient temperature.This paper describes an effective approach to analyze thermal effects in optical systems of star sensor.The star position errors,which are caused by thermo-optic effects,are calculated in an optical system of middle-precision star sensor.The results show that the star position errors are not remarkable near field angle 0°.And material matching is an effective measure in reducing the star position errors caused by changes of ambient temperature.After thermal compensation design,the maximal error is only 0.02″ when the ambient temperature changes from-20℃ to 60℃,which is about 1/7 of the original optical system's maximal error.