基于公共星检验的改进球面多边形搜索星图识别算法

摘要

To realize the rapid identification of the stars in multiple fields-of-view star trackers, a modified star identification algorithm by spherical polygon search is proposed based on common star checking to solve the ambiguity of observed star and corresponding guide star in matched star pairs, which increases the amount of computations in the original spherical polygon search star identification algorithm. Two observed star pairs made up of three observed stars are matched to guide star pairs based on angular distance. The common star connection of the two observed star pairs is utilized to kick out the wrong guide star pair matches and confirm the corresponding guide star to the observed star, which reduces the computation in the modified algorithm. Meanwhile, another observed star, not the aforementioned three observed stars, is selected to verify the matched star pairs, which improves the identification rate for “four-star pattern” is indirectly formed. Simulation results show that the modified algorithm is better than the original algorithm at both velocity and identification rate. When the star position error was between 0.1 pixel and 0.5 pixel, the mean identification time with the modified algorithm was both about 1/10 of that with the original algorithm.%为了实现多视场星敏感器的快速星图识别，针对球面多边形搜索星图识别算法面临单个星对角距匹配无法实现观测星与导航星一一对应造成计算量增加问题，提出了基于公共星检验的改进球面多边形搜索星图识别算法。使用三颗观测星形成的其中两个星对进行角距匹配，并基于两观测星对的公共星连接条件，实现了角距匹配中错误星对结果的剔除，以及匹配星对中观测星与导航星的一一对应，减少了算法计算量；同时，在验证匹配星对时另选三颗观测星之外的一颗观测星，间接实现了四星模式验证，提高了改进算法的识别率。仿真结果表明，改进算法的识别速度和识别率要明显高于原算法，且在星像位置误差为0.1~0.5像素时，改进算法的平均识别时间约为原算法的1/10。