热光效应对星敏感器测量准确度的影响

运用"热-结构-光"耦合分析方法,计算典型星敏感器光学系统(6透镜光具组,f=56 mm,相对孔径1/1.3)恒星像斑理想质心位移和亚像元内插质心偏移量,研究温度分布对星敏感器测量准确度的影响.以20℃为光学系统标定温度,计算光学系统均匀温度分布、轴向温差分布和上下侧温差分布三种条件下,星敏感器测量误差.均匀分布温度变化20℃时,星敏感器测量误差约0.07″;轴向温差10℃和20℃时,测量误差分别约为0.17″和0.31″;上下侧温差仅2℃时,测量误差就高达1.46″.计算结果表明,上下侧温差分布对星敏感器准确度影响最大,均匀温度分布影响最小.

Thermo-optic Effects on Accuracy Performance of Star Tracker

Thermo-optic effects on position accuracy of star tracker was analysised using opto-mechanical coupling method.The displacements of star centroids and sub-pixel interpolation errors,caused by three kinds of temperature distribution respectively,were calculated quantitatively in a typical optical system of star tracker.The measurement error of star tracker was about 0.07″,when uniform temperature changed 20℃.The measurement errors were about 0.17″and 0.31″,respectively,when temperature difference were 10℃ and 20℃ in axis.And it was as much as 1.46″,when temperature distribution difference between top of the optical system and the bottom was only 2℃.The results show that temperature distribution difference between the top and the bottom has serious effects on measurement accuracy of star tracker,and uniform temperature distribution has a little.