Combined Processing of Outlier and Multipath in GNSS Precise Point Positioning

The Global Navigation Satellite System (GNSS) precise point positioning (PPP) technology is inevitably affected by outlier and multipath, especially under complex environments. Based on the idea of robust estimation and multipath detection, a combined processing method considering the outlier and multipath simultaneously is proposed for GNSS PPP in this study. The GNSS observations in real complex environments were used to conduct the kinematic PPP experiment. Besides, the PPP positioning performance is carefully compared and analyzed among without the outlier and multipath processing, the traditional outlier processing, and the combined outlier and multipath processing. The results show that the proposed processing method can improve the positioning performance for GNSS PPP. Compared with the traditional outlier processing, the positioning accuracy of the proposed method is improved by 20.3%, 49.2% and 13.6% in E, N, and U directions, respectively. Hence, the proposed method considering both the outlier and multipath can effectively improve the PPP positioning performance, especially under complex environments.