BeiDou+GLONASS+Galileo多系统组合SPP稳定性和精度分析

Stability and Precision Analysis of BeiDou+GLONASS+Galileo Multi-system Combined SPP

利用间接平差法和最小二乘法原理推导了BeiDou+GLONASS+Galileo三系统组合标准单点定位(SPP)的数学模型;然后采用MGEX站的部分测站的观测数据,综合分析了BeiDou/GLONASS/Galileo不同组合模式的可见卫星数、DOP值、定位稳定性和定位精度等方面内容。试验结果表明:相比单系统(BeiDou、GLONASS、Galileo)、双系统(BeiDou+GLONASS、BeiDou+Galileo、GLONASS+Galileo),BeiDou+GLONASS+Galileo三系统组合的DOP值分别减少30%~55%、10%~50%;可见卫星数分别增加60%~120%、10%~110%。此外,在截止高度角大于30°的情况下,单系统和双系统的DOP值都较大且波动不稳定,定位可靠性和历元可用率会显著降低,而BeiDou+GLONASS+Galileo组合仍能获得比较理想的定位结果,这对于建筑物密集区、山区和卫星遮挡较为严重的恶劣条件下具有实际应用价值。

Based on the indirect adjustment method and the principle of least squares, the mathematical model of the combined standard single point positioning （SPP） of BeiDou＋GLONASS＋Galileo system is deduced.Then,using the observation data from some stations of the MGEX station,authors comprehensively analyze the number of visible satellites, DOP values, positioning stability, and positioning accuracy from different combinations of BeiDou, GLONASS or Galileo.The experimental results show that the DOP values of the BeiDou ＋GLONASS＋Galileo three-system combination is reduced by 30% ~ 55% and 10%- 50% respectively compared to the single system （ BeiDou, GLONASS, Galileo） and the dual system （ BeiDou ＋ GLONASS, BeiDou ＋ Galileo, GLONASS ＋ Galileo ）. Visible satellites increased by 60% ~ 120% and 10%- 110% respectively.In addition,with a cut-off elevation angle greater than 30°, the DOP values of single-system and dual-system are large and fluctuating.The positioning reliability and epoch availability are significantly reduced ,while the BeiDou＋GLONASS＋Galileo combination can still get better positioning results.This has practical application value under the harsh conditions of building-intensive areas,mountains and satellite shehers.