基于地月三角平动点的卫星自主定轨

Autonomous Orbit Determination of Satellites around Triangular Libration Points in the Earth-Moon System

近年提出了利用地月系平动点建立深空导航星座的设想。在受太阳摄动的真实力模型下,地月系平动点是不稳定的,从而会导致导航星座必须通过控制才能定点在特定区域。针对此问题,引入一种特殊的平动点轨道,即动力学替代轨道。平动点轨道卫星星座可利用星间测距数据自主定轨,由于动力学替代轨道具有长期稳定性,整个自主定轨过程不需要来自地面的测控支持,且定轨精度可达到观测精度。研究结果表明,观测资料的长短、导航卫星垂直白道面的运动分量都将影响到导航星间的自主定轨精度。该研究成果可以应用在以后的地月系导航星座中。

Recently, people are proposing to build a deep space navigation constellation in the Earth-Moon system which utilizes libration points of the Earth-Moon system. In the true model of the solar perturbation, the libration points of the Earth-Moon system are unstable, which leads to the navigation constellation must be controlled in a certain area. This paper introduces a special kind of libration point orbits, called as Dynamical Substitutes （DSs）, using inter-satellite range data, the autonomous orbit determination problem of DSs is studied in this paper, due to their long-term stability. As a result, during the whole process of autonomous orbit determination, no support from the ground stations is needed, and studies show that the orbit determination accuracy can reach that of the observa-tion. So, in order to obtain good Autonomous Orbit Determination （AOD） results, the data length should not be too short,and the satellite should have motion component perpendicular to the Moon’s orbital plane. The current study can be used when deploying the navigation constellation in the Earth-Moon system.