Signal quality and positioning performance of GPS/BDS-3/GLONASS/Galileo in polar regions

Growing activities in the Arctic and Antarctica call for more navigation and positioning services in these regions. The current GNSS (Global Navigation Satellite System) constellations, which have the capability of fully global positioning services, consist of GPS, BDS-3, GLONASS and Galileo. In this study, multi-GNSS observations of 2 stations from international GNSS monitoring and assessment system (iGMAS) and 10 stations from multi-GNSS experiment (MGEX) are selected to assess the signal quality and positioning performance of multi-GNSS in polar regions. After the fully operational global services of BDS-3 from July 31, 2020, this is the first time to assess the positioning performance of GPS/BDS-3/GLONASS/Galileo in polar regions. For BDS-3 and GPS, its number of visible satellites (NVS) is between 6 and 12 and position dilution of precision (PDOP) is approximately 2, which is slightly better than that of GLONASS and Galileo. As for signal to noise ratio (SNR) and multipath (MP) delay, each frequency of BDS/GPS/GLONASS/Galileo exhibits generally similar strength, and among them, the B2a signal of BDS-3 has stronger anti-multipath ability. In terms of positioning performance, the results from solution independent exchange (SINEX) are taken as the reference for more objective validation. For single-constellation, the precise point positioning (PPP) accuracy of BDS-3 is at the level of centimeters, which is equivalent to GPS, GLONASS, and Galileo. The multi-constellation PPP was analyzed with double/triple/quadruple-constellation combinations. Compared to single-constellation, the multi-constellation combination slightly improves positioning accuracy, and as the number of available satellites in multi-constellation combinations greatly increases, the convergence is accelerated. (C) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.