GEO卫星辅助的LEO通信星座定位性能研究

Research on the positioning performance of LEO communication system with the assistance of GEO satellite

由于存在较大的几何精度因子(GDOP)值,单独利用低轨小卫星通信星座进行用户定位存在定位精度低、定位时间长等缺点。在对造成低轨定位系统GDOP较大的原因进行理论分析的基础上,提出采用静止轨道(GEO)卫星辅助低轨卫星(LEO)进行定位的方案,并提出了相应的两种基于多普勒频移和到达时间差的定位算法,通过仿真对算法在该方案中的性能进行了评估。仿真结果表明,该方案可以有效地提高定位精度,减小定位时间,是一种实现低轨小卫星系统通信与导航定位兼容的简单而有效的方案。

Locating user s position only in LEO communication constellation has some drawbacks, such as low accuracy and long waiting time. This is related with a larger GDOP value of LEO system. Based on the theoretical analysis of cause of such a large GDOP, a new LEO positioning scheme with GEO satellite's assistance is proposed and two positioning algorithms based on the Doppler and TDOA characteristics are suggested. The scheme's performance with the algorithms is evaluated by simulation, and it is proved that this scheme can effectively improve positioning accuracy and reduce waiting time, hence it is a simple and resultful plan to provide navigation and positioning function in LEO small satellite communication system.