Kalman Filter-Based Integrity Monitoring for MADOCA - PPP in Terrestrial Applications

With the development of intelligent transportation systems, precise point positioning (PPP) has attracted increasing research attention because of its high accuracy and flexibility. Real-time, fast-convergence PPP can be implemented using free regional augmentation signals that broadcast correction messages for satellite orbit and clock bias. In this study, PPP was combined with Quasi-Zenith Satellite System multi-global navigation satellite system (GNSS) advanced orbit and clock augmentation (MADOCA). Furthermore, integrity monitoring was implemented for MADOCA-PPP in terrestrial applications. Localization integrity is an essential criterion for evaluating whether a navigation solution is trustworthy, and this criterion has been widely used in the GNSS. In this study, integrity monitoring was performed using an ionosphere-free combination of the GPS and GLONASS according to the corresponding MADOCA -corrected residuals. The residual characterization indicated that a Kalman filter-based chi-square test is suitable for conducting fault detection and exclusion. Simulated one or two satellite steps, and ramp faults can be appropriately excluded, which reveals the system's capability for rejecting outliers from abnormal measurements. To construct the error bound for a certain integrity risk, the protection level, which has a Student's t-distribution, was computed. The experimental results were validated in static and kinematic scenarios to assess the integrity and positioning performance of MADOCA-PPP.