在采用天文光学自主导航方式进行深空探测时, 导航星的视星等高, 为获取清晰的星图, 星敏感器焦距长、曝光时间长, 同时受探测器多种运动复合的影响, 星图易产生模糊拖尾现象, 很难用基于硬件的常规方法有效复原。研究复合运动模糊星图的建模方法, 可揭示星敏感器与导航星的真实相对运动对星图像质的影响规律, 从而用软件算法复原高像质星图, 提高星敏感器的动态性能。由于缺乏确定的参数模型, 复合运动模糊星图建模难度较大。提出了一种基于可分离模糊核的复合运动模糊星图建模的新方法, 研究星敏感器角运动和角振动对成像的影响, 并与常用的分步模糊方法比较。仿真表明: 基于可分离模糊核方法的仿真星图更符合星敏感器实际运动对星图退化的影响; 星敏感器的复合运动特别是旋转运动对质心提取效果具有显著影响, 严重时会导致星敏感器无法定姿。

In the deep space exploration, astronomical optical autonomous navigation was used. The apparent magnitude of navigation stars for optical autonomous navigation was high. In order to obtain the clear star image, the star tracker′s focal length and exposure time were long. Besides, star trackers were easily influenced by complicated motion. All these reasons resulted to the blurring and smearing star images. What was worse, it was difficult to restore the blurred star images by hardware methods. Studying the modeling method based on complicated motion was helpful to make sense the influence on the image quality which was caused by relative motion between the star tracker and the navigation star and to restore blurred star images by software methods. So that the star tracker′s dynamic performance was improved. It was hard to simulate blurred star images which were caused by the complicated motion of star trackers for the lack of definite motion models. The angular motion and vibration were analyzed and an innovative method was proposed to simulate the blurred star images and then the step-by-step simulation method was compared with the new method in this paper. The simulation results indicated that the simulation method based on the separable kernel could describe the real physical image process better than the step-by-step method and the complicated motion had great influence on the extraction errors of star spot centroids, even leading to the failure of attitude determination of star trackers.