STATIC GNSS DATA

This study investigates the influence of satellite constellation configurations on the positional accuracy of post-processed static GNSS data at the University of Benin, Ugbowo Campus. Static observations were collected at five known control points using a Tersus David30 receiver. Data was processed in Tersus Geomatics Office across seven constellation setups: GPS-only, GLONASS-only, BEIDOU-only, and their combinations. A detailed epoch-based analysis was also conducted at one control point using RTKLIB. Accuracy was assessed using coordinate residuals (∆E, ∆N, ∆H), RMSE, standard deviation, CEP, and 2DRMS, supplemented by classical
and robust statistics and time-series analysis. Results demonstrated that GPS-based solutions consistently delivered superior performance. The GPS+BEIDOU combination achieved the best accuracy (2DRMS = 0.160 m, CEP = 0.067 m), closely followed by GPS-only. In contrast, BEIDOU-only yielded the poorest results (2DRMS = 0.587 m), while GLONASS-only was notably weak and unstable. RTKLIB processing confirmed that multi-constellation setups, particularly GPS+GLONASS+BEIDOU, produced highly precise solutions with sub-centimeter standard deviations. Conversely, the GLONASS-only solution exhibited severe instability, with significant errors and outliers. Time-series analysis revealed that stable constellations maintained narrow error bands, while error spikes in other configurations corresponded directly to drops in satellite visibility