信号易遮挡地区GPS/BDS双频单历元短基线解算精度分析

Precision Analysis of GPS/BDS Dual-Frequency Single Epoch Short Baseline Solution in Signal Shadowed Regions

信号易遮挡地区GPS、BDS单系统可见卫星个数少,无法达到相对定位的最低要求。讨论了GPS/BDS组合单历元基线解算模型,在多种模拟环境下将GPS/BDS联合解算结果与GPS和BDS单系统在可见卫星数、模糊度固定成功率、定位精度等方面进行对比分析。结果表明,相对于单系统单历元基线解算,GPS/BDS组合大大增加了可见卫星数,提高了模糊度固定成功率,并在极端的观测条件下有效地改善了定位精度,使信号易遮挡地区双频单历元基线解算精度可以达到cm级甚至mm级。

This paper attempts to solve the problem that,due to the loss of visible satellites in signal shadowed regions,GPS or BDS single system cannot meet the minimum requirements of relative positioning.We first discuss the mathematical model of the GPS/BDS single epoch baseline solution.It compares GPS/BDS combined solution results with GPS and BDS single system solution results with respect to satellite visibility,ambiguity resolution success rate,and positioning accuracy in multiple simulative masking environment.The numerical results show that：compared with the single epoch baseline resolution of a single system,GPS/BDS greatly increases the number of visible satellites,improves the success rate of ambiguity,and effectively improves the positioning accuracy under extreme observation conditions.In addition,the dual-frequency single epoch accuracy can reach cm-level or even mm-level in signal shadowed regions.