Performance Assessment of Positioning Based on Multi-Frequency Multi-GNSS Observations: Signal Quality, PPP and Baseline Solution

With the advances and modernization of GPS, GLONASS, BDS, Galileo QZSS, multi-frequency multi-system joint positioning has become mainstream navigation. Therefore, it is great importance to perform a comprehensive assessment signal quality performance multi-GNSS. In this work, we used multi-GNSS observation data collected by Multi-GNSS Experiment (MGEX) International GNSS Service (IGS), Hong Kong CORS, Research Centre Curtin University. Firstly, evaluated analyzed. Then, five-system triple-frequency ionospheric-free combined PPP (IF-PPP) uncombined (UC-PPP) models are established, their in static kinematic evaluated. Finally, short baseline, medium long baseline very Based on results, three major observations made as follows. (1) The signal-to-noise ratios (SNRs) five constellations (i.e. QZSS) all above 30dB Hz multipath errors within 1m, indicating good quality. (2) For PPP, compared with IF-PPP model, convergence time UC-PPP model reduced 4.9%, 3.2%, 13.8% for BDS-2+3, GPS/GLONASS/BDS-2+3/Galileo/QZSS, respectively. However, accuracy improved 15.9%, 11.8%, 10.9%, respectively, model. increased number BDS-3 satellites, BDS achieved better results than GPS. (3) terms solution performance, GPS/GLONASS/BDS/Galileo/QZSS about 60% higher that GPS-only solution, showing significant gain due use observations.