镜筒热形变对星敏感器测量精度的影响

 空间环境温度以及阳光热效应对星敏感器测量精度有一定影响。研究镜筒热形变对星敏感器测量精度的影响,计算温度均匀分布和非均匀分布条件下,圆柱形镜筒和圆锥形镜筒热形变导致的透镜倾斜量和平移量,研究典型星敏感器光学系统中恒星像斑位置和能量分布的变化情况。在镜筒温度均匀分布条件下,温度变化20℃时,圆柱形镜筒和圆锥形镜筒的星敏感器测量误差分别为0.6″和0.9″;在镜筒温度非均匀分布条件下,镜筒上侧与下侧的温差为30℃时,圆柱形镜筒和圆锥形镜筒测量误差约为2.2″和3.3″。计算结果表明,圆柱形镜筒热稳定性优于圆锥形镜筒。

Effect of Barrel's Thermal Deformation on Measurement Error of a Star Sensor

Measurement error of a star sensor is restricted by varying ambient temperature and solar irradiance.Effect of barrel’s thermal deformation on measurement error of a star sensor is analysed in this paper.The tilting and shifting of the lens caused by barrel’s thermal deformation are calculated for a typical optical system of star sensor.Displacement of star image point and its energy distribution are analyzed.When barrel’s temperatures change uniformly 20℃,measurement errors of the star sensor are about 0.6″ and 0.9″ for cylindrical and conical barrel respectively.When temperature differences of barrel are 30℃,measurement errors are about 2.2″ and 3.3″ for cylindrical and conical barrel respectively.Results show that cylindrical barrel’s thermal stabilization is better than conical barrel’s.