基于CMOS APS的星敏感器空间辐射损伤传递机制研究

Star sensor has now become an indispensable navigation information measurement device in high-precision attitude control system of satellite. However, the bad space radiation environment will result in the performance degradation of star sensor and the reduction of attitude measurement precision. The cause of this problem has been analyzed at home and abroad is that displacement damage of the imaging device CMOS APS caused by the space proton irradiation. However, the mechanism has not been reported that how the changes of sensitive parameters induced by displacement damage transmitting from CMOS APS to the output of star sensor system, resulting in the degradation of system performance parameters..In this project, star sensor based on CMOS APS is taken as the research object. The performance degradation mechanism of star sensor caused by proton irradiation is mainly studied. By establishing the correlation and quantitative relationship among the spatial radiation, the displacement damage sensitive parameters of CMOS APS and the performance parameters of star sensor, the transmission mechanism from CMOS APS device parameters degradation to star sensor system parameters degradation is revealed. Finally, predicting method with performance parameters degradation of star sensor after irradiation is obtained. The influence of space radiation on star sensor performance parameters is analyzed innovatively from a system level point of view. The implementation of this project lays the foundation for the research of star sensor attitude error measurement and in-orbit correction technology.

星敏感器如今已成为卫星高精度姿态控制系统中不可缺少的导航信息测量装置，然而恶劣的空间辐射环境会导致星敏感器性能退化、姿态测量精度降低。国内外已分析出造成这一问题的原因是空间质子辐照导致成像器件CMOS APS的位移损伤，但CMOS APS位移损伤敏感参数的变化是如何传递到星敏感器系统输出端从而导致系统性能参数退化的机制还未开展研究。.本项目以基于CMOS APS的星敏感器作为研究对象，重点研究质子辐照导致星敏感器性能退化的机理。通过建立空间辐射和CMOS APS位移损伤敏感参数、星敏感器性能参数之间的相关性和量化关系，揭示CMOS APS器件参数退化到星敏感器系统参数退化的传递机制，获得星敏感器受辐照后性能参数衰退预测方法。本项目创新地从系统级的角度分析了空间辐射对星敏感器性能参数的影响。本项目的实施为星敏感器姿态测量误差预测和在轨修正技术的研究奠定基础。

本项目以基于CMOS APS的星敏感器作为研究对象，针对 CMOS APS辐照退化对星敏感器性能的影响机制和空间辐射、CMOS APS 位移损伤敏感参数、星敏感器性能参数之间的对应关系与量化关系两个科学问题，开展了基于CMOS APS的星敏感器空间辐射损伤传递机制研究。. 通过项目的实施，搭建了星敏感器实验室测试系统和外场观星测试系统，建立了星敏感器星点质心定位精度、星对焦距精度、极限探测星等的测试表征方法。通过开展伽马、质子辐照试验，获得了星敏感器星点质心定位精度、星对焦距精度、极限探测星等随辐照的变化规律。利用电离损伤、位移损伤分离技术获得了CMOS APS位移损伤敏感参数和星敏感器关键性能参数之间的对应关系。通过理论推导和试验支撑获得了CMOS APS位移损伤敏感参数对星敏感器关键性能参数影响的定量评估公式。. 本项目的实施为星敏感器在轨姿态测量误差预测和修正技术的研究奠定基础，更可以为高性能星敏感器的设计提供一定的理论依据和技术支撑。