BDS/GPS/GLONASS多模融合伪距单点定位性能比较与分析

Comparison and analysis of BDS/GPS/GLONASS multi-mode fusion pseudo-range positioning performance

利用最小二乘法原理推导了多系统组合伪距单点定位的数学模型.然后,对不同组合模式(BDS、GPS、GLONASS、BDS/GPS、BDS/GLONASS、GPS/GLONASS和BDS/GPS/GLONASS)的单点定位进行解算和试验比较分析.试验结果表明:多系统(BDS/GPS/GLONASS)组合单点定位与单系统相比,多系统组合具有更多的可视卫星,从而获得了较小的PDOP值,随着截止高度角的增加,可见卫星数逐渐减少,定位精度也会随之降低.然而,在观测条件恶劣、截止高度角较大情况下,单系统和双系统定位精度都较差,三系统组合仍能获得比较好的定位精度,1 d内的定位精度均在10 m以下,优于GPS单点定位精度.使其在建筑物密集区、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.

The mathematical model of multi-system combined pseudorange single point positioning was derived using the principle of least squares. Then, the single point positioning of different combination modes(BDS,GPS,GLONASS,BDS/GPS,BDS/GLONASS,GPS/GLONASS and BDS/GPS/GLONASS) is solved and analyzed comparatively. The experimental results show that: Compared with single-system positioning of multi-system(BDS/GPS/GLONASS), multi-system combination has more visible satellites, and thus smaller PDOP values are obtained, with increasing cut-off angle, It can be seen that the number of satellites is gradually reduced, and the positioning accuracy is also reduced. However, under the conditions of poor observation conditions and large cut-off angles, the single-system and dual-system positioning accuracy is poor, and the three-system combination can still obtain better positioning accuracy. The positioning accuracy within 1 d is less than 10 m, which is better than GPS single point positioning accuracy. It has practical application value in harsh conditions where buildings are densely packed, mountainous areas and satellites are blocked more severely.