基于多GNSS融合的GPS PPP模糊度固定方法

The Method of Ambiguity Fixing for GPS PPP Based on Multi-GNSS

通过BDS/GPS/GLONASS组合的方式加速PPP的收敛,利用整数相位钟法实现GPS PPP模糊度的固定,并通过6个MGEX测站的数据进行PPP动态实验。结果表明,固定解的精度优于浮点解,而基于BDS/GPS/GLONASS融合的PPP固定解定位精度优于单GPS PPP固定解;GPS固定解PPP平均模糊度首次固定时间(TTFF)为46.1min,而基于BDS/GPS/GLONASS融合的固定解PPP首次固定时间仅为25.8min,相应的模糊度固定率也由78.6%增加到87.4%。

In precise point positioning, high-precision floating ambiguity is important to ensure that integer carrier phase ambiguities are resolved reliably. However, a convergence time of several tens of minutes is required to obtain high-precision floating ambiguity. In this paper, BDS/GPS/GLONASS combined PPP are carried out to accelerate convergence, and then we use the inter phase clock method to realize the GPS PPP ambiguity fixing. Six MGEX stations are used for the kinematic PPP test. The results show that, first, compared with ambiguity-floating PPP, ambiguity-fixed PPP obtains better positioning accuracy, and the BDS/GPS/GLONASS ambiguity-fixed PPP further improves positioning accuracy. Second, the TTFF （time to first fixed） for GPS ambiguity-fixed is 46.1 min, while only 25.8 mix for BDS/GPS/GLONASS ambiguity-fixed, which reduces 44.0%. Third, the ambiguities fixed rate raise from 78.6% to 87.4%, improving nearly nine percentage points.