像差对星敏感器星点定位精度的影响

Aberrations effect on position accuracy of star sensor

光学系统星点定位精度是表征星敏感器性能的一个重要指标,像差对该精度有一定影响。分析光学系统像差对星点定位精度的影响,在计算典型中等精度星敏感器光学系统星点定位误差的基础上,提出用实际测得的星点光斑能量质心位置计算理想位置的误差补偿新方法。计算结果表明:像差对高精度(如角秒级)星敏感器姿态测量精度的影响不可忽略;采用星点定位误差补偿后,星敏感器三轴姿态测量误差RMS值分别为0.38″,0.38″,5.77″,仅为原来的1/17。

Position accuracy of star is an important parameter of star sensor＇s performance, and it is restricted by the aberrations of the optical system. A new compensatory scheme of aberrations＇ effects is described in optical systems of star sensors. The star position errors, which are caused by aberrations, are calculated in an optical system of middle-accuracy star sensor. And a star position compensatory scheme is proposed. The results show that the star position errors, which are caused by aberrations, are important in high-accuracy star sensor, such as arcsecond level. And after implementing the star position error compensation scheme, the error components are reduced to 0.38″, 0. 38″, 5.77″ about the X, Y, Z axes respectively, which are about 1/17 of the original.