星光折射导航星的改进三角识别捕获

The Capture of Grazing Star Based on the Modified Triangle Identification Algorithm

高精度星光折射间接敏感地平的自主导航方法,目前被国内外尤为关注。本文通过对星光折射导航观测对象———导航星捕获的研究,采用了改进的三角匹配算法并结合恒星星表,确定出导航观测星星光方向,同时依据对飞行器在轨观测星的几何关系推导,利用Unscented卡尔曼滤波算法确定航天器的在轨位置和速度。该方法能比较真实地模拟飞行器实际在轨的导航情况。仿真表明,真实星表导航精度大于人造星场;通过比较导航系统捕获20,40,60,80颗折射星的4种情况,可知捕获到的导航星的数量越多,导航精度也随之提高。

Currently,the method of autonomous navigation by stellar refraction is particular concerned in both domestic and oversea.The study of acquiring the navigation stars is focused to identify the direction of starlight by using the modified triangle identification algorithm to capture grazing star and combining the information of bright star catalog.Meanwhile,by deriving from the geometric relations of observable star while spacecraft is in orbit,the position and the velocity of the spacecraft can be calculated by the Unscented Kalman Filter.The actual situation of navigation can more factually simulated by using this method.And it is verified by simulation results that using of the bright star catalog is better than using of the artificial star field to simulate refractive navigation stars.By analyzing the different navigation results when the navigation system captures 20/40/60/80 grazing stars,the results show that the more navigation stars is being captured so that the higher navigation precision is reached.