适用于小视场星敏感器的导航星表构建方法

导航星表构建是星敏感器设计阶段的重要工作.对于小视场,受限于恒星分布规律,易出现导航星表空洞问题.为解决小视场条件下均匀完备导航星表构建问题,对基于球面螺旋基准点的导航星表构建方法进行了改进:摒弃了原方法通过改变球面螺旋基准点数量和位置重新构建导航星表的思路,转而通过增选部分恒星来达到减少星表空洞的目的.设立了描述恒星消除星表空洞能力的权值,并以该权值递减顺序开展恒星增选;同时,设计了增选恒星距离阈值条件以保持增选后导航星表的均匀性.仿真表明,在4圆形视场条件下,相对于原方法,文中方法得到的导航星表,总星数减少708颗,均匀性指标提高约44%,而星表空洞变化较小,显示了较好的性能.

Guide star selection method for star tracker with thin field of view

Guide star selection is a crucial part of star tracker design. For thin field-of-view star tracker, guide star catalogholes are common as stars are not evenly distributed. To optimize the guide star selection for star tracker with thin field of view, the selection method based on spherical spiral points was modified. Building a new guide star catalog by increasing the number and changing the positions of spherical spiral points, which was usually adopted, was abandoned. Some new stars which can effectively decrease guide star catalogholes into the guide star catalog were proposed. The weights to measure stars' ability of decreasing guide star catalog holes were constructed and the adding star process was carried out on the order of the weights descending. And the new star added into guide star catalog was required far away from the guide stars to keep the guide stars even. Simulations expressed that the modified method got less and evener guide stars than the original method with similar guide star catalog holes, which shows the superiority of the modified method.