BeiDou、Galileo、GLONASS、GPS多系统融合精密单点

Precise Point Positioning with Multi-constellation Satellite Systems:BeiDou、Galileo、GLONASS、GPS

随着中国BeiDou系统与欧盟Galileo系统的出现以及俄罗斯GLONASS系统的恢复完善,过去单一的GPS导航卫星系统时代已经逐步过渡为多系统并存且相互兼容的全球性卫星导航系统（multi-constellation global navigation satellite systems,multi-GNSS）时代,多系统GNSS融合精密定位将成为未来GNSS精密定位技术的发展趋势。本文采用GPS、GLONASS、BeiDou、Galileo 4大卫星导航定位系统融合的精密单点定位（precise point positioning,PPP）实测数据,初步研究并分析了4系统融合PPP的定位性能。试验结果表明：在单系统观测几何构型不理想的区域,多系统融合能显著提高PPP的定位精度和收敛速度。4大系统融合的PPP收敛速度相对于单GNSS可提高30%~50%,定位精度可提高10%~30%,特别是对高程方向的贡献更为明显。此外,在卫星截止高度角大于30°的观测环境下,单系统由于可见卫星数不足导致无法连续定位,而多系统融合仍然可以获得PPP定位结果,尤其是水平方向具有较高的定位精度。这对于山区、城市以及遮挡严重的区域具有非常重要的应用价值。

With the appearance of China＇s BeiDou system and EU＇s Galileo system and the restoration and improvement of Russia＇s GLONASS navigation system,the single GPS navigation satellite system has been gradually developed into multi-GNSS（multi-constellation global navigation satellite systems）.Multi-GNSS with precise positioning will become the development trend of GNSS precise positioning in the future.Using the observation data collected by PPP（precise point positioning）,which integrates the four major satellite navigation systems of GPS、GLONASS、BeiDou and Galileo,this paper conducts a preliminary study and analyzes the positioning performance of multi-system PPP.According to the experiment,in areas where single system observation geometrical configuration is unsatisfactory,multi-system integration can greatly improve the positioning accuracy and convergence rate of PPP.The convergence rate of multi-constellation PPP is 30%to50% higher than that of single GPS,and the positioning accuracy can also be improved 10%to 30%,especially in terms of elevation direction.Besides,under observation circumstance where the end elevation angle of satellite is larger than 30 degrees,single GPS fails to carry out continuous positioning due to lack of visible satellites,while multi-constellation PPP can still get positioning results,with relatively high accuracy in horizontal direction especially.