适用于地面应用系统的导航星数据库的建立

Guide Star Sub-catalog Generation for Ground Application System

简要介绍了所采用的恒星运动标准模型、历元转换及误差传播基本原理。给出了一种导航星数据库的构建方法,该方法以Hipparcos星表为中心,以星敏感器光学系统的观测极限为星等阈值,联合多个星表,通过精密历元转换,引入位置精度阈值以确保卫星姿态确定角秒量级的精度;引入辅助导航星以提高星图识别率和识别速度。蒙特-卡罗仿真结果表明利用该导航星数据库在有伪星存在的情况下星图识别率96.7%以上,同时识别视场内5颗星的识别速度在0.3秒以下,加入189颗辅助导航星后,在导航星总数提高至6261颗时,星图识别速度却提高了6%以上。

The standard model of stellar motion, epoch transformation and associated error propagation are introduced at first. Then a method of constructing guide star database is proposed. This method based on the Hipparcos catalog, chose the detection limit of star tracker＇ s optics as the star magnitude threshold. With the help of the information of other three star catalogs, through the rigorous treatment of epoch transformation, the star＇ s position of the same epoch is got. Then the threshold of position precision is introduced, which can meet the precision of attitude determination in arc-second level. The additional guide star is come into use for improving the accuracy and speed of star identification. Through Monte-carol simulation, it is shown that the star identification accuracy is higher than 96.7%, the speed of identify 5 stars in the same field of view is faster than 0.3 second, after adding the 189 addition guide stars, the total number of guide stars is up to 6261, but the speed of star identification is improved more than 6 %.