基于参考轨道的Walker星座相对相位保持策略

针对高轨道Walker全球星座相对相位保持问题,在分析星座几何结构演化规律基础上,提出了一种基于动态调整参考轨道的星座相对相位保持策略.该参考轨道的半长轴取星座所有卫星的平均轨道半长轴的平均值,通过计算各卫星相对参考轨道的相对相位偏差以及变化率,而后根据有关维持的约束条件来选择合适的卫星进行站点保持,使得所有卫星的相对参考轨道的相位偏差不超过允许值.当一旦有卫星进行了站点保持,则参考轨道就重新统计确定.文章通过一个12颗MEO卫星构成的Walker-δ星座的分析算例,表明这种相对保持策略可以减少星座的站点维持次数.本文提出的方法可以为我国今后卫星导航星座的维持提供参考.

A Relative Phase-Keeping Strategy of Walker Constellation Based on Reference Orbit

According to the relative phase-keeping of Walker constellation in high orbits,based on analysis of evolveing law of the constellation geometry,a relative station-keeping strategy of constellation based on dynamically adjusting reference orbit is presented in this paper. The mean value of semimajor axis of average orbit is chosen as the semimajor axis of the reference orbit. The relative phase difference and its rate are computed,then according to the constraint conditions of orbit maintenance,an appropriate satellite is chosen to perform station-keeping to make all phase difference between each satellite and the reference orbit not exceed a permissible value. Once the station-keeping of one of the satellites is performed,the reference orbit must be recomputed. A Walker-δ constellation composed of 12 MEO satellites is taken as a analytical sample in this paper. The simulation result shows that the relative station-keeping strategy is helpful for decreasing times of orbit maintenance. The approach gives a reference to orbit maintenance of satellite navigation constellation of China in the future.