Galileo/北斗组合系统GDOP改善方法研究

从理论上来说,导航卫星数量越多,可提供的几何精度下降因子(GDOP)就越小。但是在进行Galileo/北斗组合系统仿真时,却发现其GDOP反而变差。文中对此进行了理论分析,指出出现该现象的原因在于两个卫星导航系统存在时间差,并且其中一个系统的可见星数过少。为解决该问题,文中提出播发系统间时差的方法,可使组合系统的GDOP相对单系统得到一定的改善。仿真结果表明,该方法可以改善GDOP。

Research on the Improvement of GDOP in the Galileo/Beidou Combined System

Theoretically,the more visible satellites are used for navigation,the value of GDOP(Geometric Dilution of Precision) provided by them is smaller.However the simulation result shows that the GDOP of Galileo/Beidou combined system is bigger than that of Galileo system.This paper analyzes the problem theoretically,points out that the reason of the forenamed problem is the time bias between the Galileo and Beidou systems,and finds that there are few visible satellites provided by the Beidou system.The method of broadcasting the time bias between the two systems is put forward to improve the GDOP performance.The feasibility of this method is proved by the simulation.