GNSS Multi-Frequency Multi-System Highly Robust Differential Positioning Based on an Autonomous Fault Detection and Exclusion Method

GNSS multi-frequency multi-system carrier phase differential positioning has become the main technology used in high-precision positioning. Until recently, the fault detection and exclusion (FDE) methods for multi-frequency multi-system carrier phase differential positioning mostly focus on procession of errors in the carrier phase domain, which cannot exclude all the faults causing a faulted baseline resolution, e.g., a fault that occurs in resolution process. Besides, the multi-fault of multi-frequency in the carrier phase domain cannot be identified due to the multi-frequency carrier phase observation errors' high correlation. We present a method of autonomous FDE based on multi-frequency multi-system carrier phase differential positioning. It focuses on the procession of errors in the position domain, and detects and excludes the faults in different frequency baseline resolutions caused not only by measurement fault as traditional method, but also the resolution fault, which can enhance the robustness and accuracy of the differential positioning system. The experimental results show that the method can effectively detect and exclude the failure of different frequency baseline resolutions and then the accurate multi-frequency multi-system positioning results can subsequently be effectively fused. The proposed method improves the accuracy and robustness of the differential positioning system.