星敏感器动态精度评价方法

Evaluation method of star sensor dynamic accuracy

针对现有精度评价方法无法有效计算星敏感器在大动态条件下精度的问题,基于星敏感器成像模型与星对角距的不变性,提出了一种星敏感器动态精度评价方法。阐明了该方法的原理,提出了计算流程和统计方法。基于风云卫星在轨数据,对比了该方法与常用的滑动窗口法的处理结果,分析了两种方法在小角速率条件下处理的等价性,验证了该方法的可行性。基于地面观星数据,分析了两型星敏感器在不同动态条件下的测量精度。与现有的动态精度评价方法相比,该方法可有效地剥离动态过程中测试系统引入的误差,更真实地反映动态条件下星敏感器的实际测量精度。

Aiming at the problem that the existing accuracy evaluation methods can not effectively calculate the accuracy of star sensor under large dynamic conditions, a dynamic accuracy evaluation method was proposed based on the imaging model of star sensor and the invariance of star angle distance. The principle was clarified,and the calculation flow and statistical method were proposed. Based on the in-orbit data of FY satellite, the processing results of the proposed method and the traditional sliding window method were compared and the equivalence of the two methods under the same condition of small angular rate was analyzed, which verifying the feasibility of the proposed method. Based on the ground observation data, the measurement accuracy of two types of star sensors under different dynamic conditions was obtained. Compared with the existing dynamic accuracy evaluation methods, this method can effectively peel off the errors introduced by the test system, and more truly reflect the actual measurement accuracy of the star sensor under dynamic conditions.