Investigation of GLONASS and Galileo Hybrid Operation for Improved Positioning Precision in Nigeria

Abstract

Global Navigation Satellite Systems provide positioning, navigation and timing services, but standalone performance in equatorial Nigeria can be affected by satellite geometry, multipath and ionospheric variability. This study compared GLONASS-only, Galileo-only and combined GLONASS-Galileo processing at the LAUTECH GNSS Laboratory, Ogbomoso, Nigeria (8.170544°N, 4.268928°E; 403.411 m ellipsoidal height). A u-blox ZED-F9P receiver tracked GLONASS L1OF/L2OF and Galileo E1/E5b during 24-hour sessions at 4 Hz in May, June and August 2025. RTKPOST used standalone single-point positioning, broadcast ephemerides and ionospheric corrections, the Saastamoinen tropospheric model and a 15° elevation mask; carrier-phase ambiguity resolution was not applied. Valid-day coverage varied by metric. Daily NSV used 14, 13 and 14 paired days in May, June and August, while visibility duration used 14, 13 and 13 days. Galileo had higher daily mean NSV than GLONASS in each month (paired Wilcoxon p=0.00024), and this ordering remained when NSV was restricted to the 12 calendar days common to all months. Galileo E5b also had higher monthly hourly mean C/N₀ than GLONASS L2OF. Daily latitude, longitude and altitude standard deviations were lower for Galileo than GLONASS in every month (all paired p≤0.00012). The 2DRMS, CEP, SEP and MRSE curves were lowest for the combined solution, but these quantities describe scatter around the daily mean and therefore measure precision rather than absolute accuracy. Because the retained thesis contained the containment results only as a plotted series without a traceable dated numerical table, that comparison is treated as descriptive. The results support improved repeatability from combined processing at this site, subject to the unequal standalone signal structures and the limits of the retained data.