GPS/BDS混合双差分RTK定位方法及结果分析

An Algorithm and Results Analysis for GPS+BDS Inter-System Mix Double-Difference RTK

提出一种单/双频GPS/BDS双系统融合的混合双差分RTK处理办法,推导出GPS/BDS混合双差分模型,并给出模型中不同系统观测值之间的时延偏差不一致、观测频率不一致问题的解决方法。与目前的标准双差方法相比,混合双差方法增加了一颗卫星的观测方程,其观测信息利用更为充分。推导结果表明,当截止高度角为50°时,对于单/双频RTK,模糊度固定正确率分别从47.96%和82.16%提高到61.86%和85.75%,同时模糊度固定的错误拒绝率分别从56.23%和7.46%降低到43.61%和1.85%。

In this contribution, an algorithm for single- and dual-frequency GPS/BDS inter-system mixed double-difference RTK is presented. We derive the mathematical model and discuss the solution to solve the problem caused by different system time delay error and different frequency of GPS and BDS. Compared to system-specific double-difference, this method uses more sufficient information. In case of high cut-off angle or few visible satellites, this can significantly improve the success rate of ambiguity resolution （AR） and reduce the false-rejected rate. When the cut-off angle is 50%, the re- sults show that compared to system-specific double-difference, for single-frequency RTK, the inter- system mixed double-difference RTK improves the correct rate of AR from 47.96% to 61.86% and re- duces the false-rejected rate of AR from 56.23% to 43.61%. For dual-frequency RTK, it improves the correct rate of AR from 82. 16% to 85. 75%, and reduces the false-rejected rate of AR from 7.46 % to 1.85 %.