An analysis of satellite visibility and single point positioning with GPS, GLONASS, Galileo, and BeiDou-2/3

Global Navigation Satellite Systems (GNSSs) have greatly developed over the last decade, so that, in addition to GPS and GLONASS, we have seen the emergence of the European Galileo and the Chinese BeiDou systems. There are presently a sufficient number of satellites in each GNSS constellation for single-system positioning purposes. Satellite visibility and single point positioning (SPP) are two basic evaluation tools in the field of GNSS data analysis. We have assessed the performance of the currently available GNSS constellations in terms of satellite visibility and SPP with the single-system approach. Visibility analysis results show that with 5- and 10-degree elevation mask angles, GPS-only, GLONASS-only, Galileo-only, and BeiDou-3-only medium earth orbit satellites in view have more limited availability in middle latitudes than in polar areas. Hybrid constellations including BeiDou-2 and combined BeiDou-2/3 exhibit a dominant longitudinal and latitudinal visibility pattern over the Asia-Pacific region. Ionosphere Free (IF) linear combination of code observations and precise orbits and clocks were used in SPP analysis. SPP results show that the horizontal and vertical RMSE values for Galileo-only case are more stable and are lower compared to the GPS-only, GLONASS-only, and BeiDou-only (BDS-2 and BDS-3) cases. Also, BeiDou performance has been significantly improved after middle of the 2020.