BDS-3 PPP模糊度固定实现及精度评估

精密单点定位(PPP)模糊度固定(AR)能够显著提升精密定位的收敛速度和精度。通过在BDS-2和BDS-3之间添加系统间偏差的方法实现BDS-3的模糊度固定，并基于全球MGEX测站静态、仿动态数据和车载实验数据全面评估了BDS-3模糊度固定的效果。结果表明，相对于浮点解，BDS-3 PPP模糊度固定能够显著提升PPP的精度，在东北天3个方向上静态解算精度提升依次为37.4%、26.2%和20.1%;仿动态解算精度提升依次为38.3%、27.2%和11.1%;车载动态实验BDS-3模糊度固定精度在三维方向上综合提升为40.4%。此外，模糊度固定后，以浮点解稳定后的两倍定位精度为基准，在东北天方向上，静态定位时间提升程度依次为63.5%、64.0%和40.3%;仿动态定位时间提升程度依次为58.7%、56.8%和25.4%;车载实验在三维方向的收敛时间为30.0 min。以上结果证明了所提方法的有效性及BDS-3模糊度固定的性能提升。

Implementation of BDS-3 precise point positioning ambiguity resolution and accuracy evaluation

Precise point positioning (PPP) ambiguity resolution (AR) can significantly improve the accuracy and convergence speed of precision positioning. The ambiguity resolution of BDS-3 is achieved by adding internal system bias between BDS-2 and BDS-3, and the effect of BDS-3 PPP ambiguity resolution is comprehensively evaluated based on static data, simulated kinematic data from MGEX stations and real-time data from vehicle-borne experiments. The results show that, compared with the float solution, the BDS-3 PPP ambiguity resolution can significantly improve the accuracy and convergence speed of PPP, with the static accuracy improvement of about 37.4%, 26.2%, and 20.1% in the three directions of the east, north and up, respectively. For the simulated kinematic BDS-3 PPP ambiguity resolution the accuracy is improved by about 38.3%, 27.2%, and 11.1%. For real-time data, the accuracy after ambiguity resolution is improved by 40.4% integrated in the 3D direction. In addition, based on twice the positioning accuracy of the float solution stabilized in the east, north, and up directions after BDS-3 PPP ambiguity resolution, the static positioning time can be improved by 63.5%, 64.0%, and 40.3%, respectively and the simulated kinematic positioning time can be improved 58.7%, 56.8% and 25.4%, respectively and the convergence time of the vehicle-borne experiment in the 3D direction is 30.0 min. The above results prove the effectiveness of the proposed method and the improvement of PPP ambiguity resolution.