北斗/GPS组合伪距单点定位性能测试

Performance Test of Beidou/GPS Combined Pseudorange Single Point Positioning

对北斗/GPS组合伪距单点定位方法进行性能测试。考虑北斗和GPS导航系统在时间、坐标系统等方面的异同点,建立北斗/GPS组合伪距单点定位模型。以北京和西安为例,考察可见卫星数、定位精度和可用性,与单系统测试结果进行对比。北斗/GPS组合系统能够在无遮挡情形下观测到18颗及以上的卫星数目,在半边遮挡和城市街道/峡谷遮挡的情形下观测到的卫星数目也明显高于单系统。北斗/GPS组合系统平面方向、高程方向的定位偏差远远低于北斗导航系统,仅略低于GPS导航系统,其原因归结于北斗导航系统的定位偏差较大。北斗/GPS组合系统相比单系统具有更好的可用性。

Performance test is carried out for Beidou/GPS combined pseudo range single point positioning method. Considering the similarities and differences between Beidou navigation system and GPS navigation system in aspects including time and coordinate system, the Beidou/GPS combined pseudorange single point positioning model is established. By taking Beijing and Xi＇an as examples, the visible satellite number, positioning accuracy and availability are investigated and compared with the single system. The Beidou/GPS system can detect 18 or more satellites in the absence of occlusion. The number of satellites observed in the case of half occlusion and urban street/canyon occlusion is also significantly higher than that of the single system. The positioning error of Beidou/GPS combination system is far lower than that of Beidou navigation system, but only slightly lower than that of GPS navigation system. The reason is that the positioning error of Beidou navigation system is larger. Beidou /GPS composite system has better availability than single systems.