联合星间测距和测速的导航星座自主定轨研究

Autonomous Orbit Determination of Navigation Constellation Based on Inter-Satellite Ranging and Ranging Rate

导航卫星通过星间观测完成定位,是提高星座生存能力的一项重要技术。在测距资料的基础上,增加测速资料进行定轨。给出了基于星间观测的定轨数学模型,证明了联合测距和测速的定轨同样存在秩亏问题,使用参数加权平差算法,顾及先验信息对星间观测资料进行平差,以Walker星座为例对算法性能进行评估。结果表明:增加测速资料后,星座位置精度略有提高,速度精度显著提高。

Determination of the positions of navigation satellites through inter-satellite observations is very important for survival of a navigation constellation.Besides ranging data,range rate data is added to the process.The mathematical model of constellation positioning is presented and the existence of rank-deficient problem is demonstrated.Then,a parameter-weighted algorithm in which priori information is considered for adjustment is chosen to adjust inter-satellite ranging data.Finally,the algorithm performance is illustrated with the example of a Walker constellation.The results indicate that the accuracy of position is slightly improved while the accuracy of velocity is significantly improved after introduction of range rate data.