顾及星像点分布的恒星相机在轨检校

由于卫星发射前后以及在轨运行过程中,环境因素的变化都可能引起恒星相机参数发生改变,从而导致星敏感器姿态测量精度下降.将多片空间后方交会方法应用于恒星相机的在轨检校.在利用该方法检校时,实验发现检校结果的精度受到参与检校的恒星影像上星像点分布的影响,由此进一步提出了凸包面积百分比准则,该方法自动选取分布较好的影像用于检校,有助于提高检校精度.实验结果证明:基于后方交会进行恒星相机在轨检校时,利用凸包法选取的影像片进行检校的精度明显优于未选片时检校的结果. 

On-orbit calibration of stellar camera considering distribution of star image points

Although the parameters of the stellar camera are accurate by the ground calibration in advance, they will change due to the intense vibration in the process of the satellite launch or the change of space environmental factors such as the temperature, the atmospheric pressure, etc. The on-orbit calibration method based on the spatial resection with multi-images was applied to the stellar camera. The percentage of the convex hull area out of the star image was employed to choose the stellar image with good distribution since the calibration accuracy is related to the distribution of the star image points. The experiment result indicates that the calibration accuracy based on the selected images is better than that based on all the stellar images.