高精度星敏感器噪声与定位精度研究

Study on Noise and Positioning Precision of Star Sensors

星敏感器定位精度是星敏感器最重要的性能指标。噪声是影响星敏感器定位精度的重要因素。文章基于矩心算法建立了星敏感器的定位精度模型,对星敏感器主要噪声所带来精度误差进行了推导,结果显示,开窗、积分时间、温度直接影响噪声大小,进而影响星敏感器的定位精度。利用基于CCDTC237的星敏感器,通过实验,定量地分析出了三种因素对于星敏感器定位精度的影响,实验结果显示,三种因素中,温度和积分时间对星敏感器定位精度的影响最大。

Positioning precision is the most important character of star sensors,and noise is one of the key factors that restrict the positioning accuracy. The mathematical models of the positioning accuracy is built based on centroid algorithm. Errors in positioning caused by noise are analyzed. The results show that the size of the window,integral time and temperature will directly affect the noise,thus affecting the positioning accuracy too. Experiments on the star sensors base on CCD TC237 show that the integral time and temperature are the primary factors that affect the positioning precision.