全球精密单点定位性能评估

随着中国北斗三号卫星导航系统（BDS-3）全面建成与开通，北斗卫星导航系统已步入了新发展阶段，基于BDS-3实现全方位、多层次、高精度应用已成为地学研究中一项基本任务。利用全球最新均匀分布的10个MGEX跟踪站，分别从24 h内接收到的卫星数、卫星位置精度因子（PDOP）、卫星数据解算完整率和双频非组合精密单点定位（PPP）静态/动态定位精度等方面系统深入地评估了BDS-3在全球范围内的可用性。结果表明，测站对卫星跟踪能力与配备的接收机类型和区域位置有强相关性，单BDS-3卫星在全球范围内具有较强的连续定位能力，当使用SEPT POLARX5和JAVAD TRE_3接收机的情况下，数据解算完整率可达100%。此外，水平方向和高程方向定位精度分别优于2 cm和3 cm，并且在联合使用BDS-2和BDS-3定位的条件下，可使得静态定位精度在东、北和高程方向进一步提升37.6%,25.3%和38.9%。

Evaluation of global precise point positioning performance for BDS-3

With the full completion and opening of China''s BeiDou-3 navigation satellite system(BDS-3), the BeiDou navigation satellite system has entered a new stage of development. The all-around, multi-level and high-precision application based on BDS-3 has become a basic task in geological research. 10 MGEX tracking stations evenly distributed around the world are used to comprehensively evaluate the global availability of BDS-3 in terms of the number of satellites in 24 h, position dilution of precision(PDOP), satellite data solution completeness rate and dual-frequency uncombined precise point positioning(PPP) static/dynamic positioning solution. The results show that the satellite tracking capability of the station is strongly correlated with the type of equipped receiver and the regional location, the single BDS-3 satellite has strong continuous positioning capability worldwide, and the data solution completion rate can reach 100% when using the SEPT POLARX5 and JAVAD TRE_3 receiver. The horizontal and vertical direction positioning accuracy are better than 2 cm and 3 cm, respectively. Besides, under the condition of combining BDS-2 and BDS-3 positioning, the static positioning accuracy is further improved by 37.6%, 25.3% and 38.9% in the east, north and elevation directions.