地面星模拟器设计与实现

Algorithm Design and Implementation of Ground Star Simulator

为了满足在地面对星敏感器进行误差标定及功能测试时的实时性要求,及避免因导航星漏选现象引起的检测误差,提出了一种改进的全天球分区动态星图仿真算法。它可以实现飞行器任意时刻发射、任意姿态下的在轨星图仿真。算法中充分考虑了天球上赤经弧长随纬度增加而逐渐缩短的情况,对传统的赤经赤纬划分天球的方法进行了改进,提出了一种新的天区划分,采用新的分区检索方法搜索导航星,既避免了导航星的漏选也提高了星图更新频率。分析了星点光斑的数学模型,使得星图仿真更加真实。对星图因动态产生的扫尾现象进行了仿真,可以很好地仿真飞行器在轨高动态情况下星敏感器的实际工作情况。

In order to realize the error analysis and functional testing of star tracker on the ground, a dynamic simulation algorithm for star map based on improved celestial sphere was proposed. This algorithm can complete sim- ulation of star map in - orbit whenever the aircraft launched and at any attitude. A new method of space district divid- ing was also presented in order to improve the traditional method of space district divided by ascension and declina- tion, and fully considered declination arc length was gradually shortened with latitude increasing. It can avoid leakage of the navigation star selection, and also can improve the efficiency of searching. Mathematical model of star spot was analyzed, and it can make the simulation image more realistic. In addition, mop - up phenomenon of dynamical star image was simulated, which can well simulate the actual work case of star tracker in - orbit with high dynamic.