一种双星定姿方法的误差分析

Error Analysis of a Double-star Attitude Determination Method

对一种双星定姿方法的误差进行了理论分析。该定姿方法用一个星敏 感器先后观测两颗导航星,并且对每颗导航星进行多次观测,以提高定姿精度。 本文对平台失调角估计误差的统计特性进行了分析,推导出了平台失调角估计 误差方差的表达式,给出了平台失调角估计误差与两颗导航星星矢量夹角β以 及观星次数N之间的关系,该结论对于工程实践中对β和N的选择具有指导意 义。

Based on a double-star attitude determination method, a theoretical error analysis is carried out in this paper. On the presence of gyro drift, the estimation error of the platform misalignment is influenced by the cross angle β of the two-navigation-star vectors together with the number N of star observation,then the relative relationship is given and the result is instructive for engineering practice.