Investigation of GPS+GALILEO Satellite Hybrid Operation towards Seamless and Improved Operation in Nigeria

Abstract

In low-latitude regions, ionospheric conditions can degrade Global Navigation Satellite Systems (GNSS)
accuracy, this study investigates the performance of Global Positioning System (GPS), Galileo, and
combined GPS+Galileo positioning in a low-latitude environment over Ogbomoso, Nigeria, using dualfrequency u-blox ZED-F9P observations collected at 4 Hz in May 2025. A static reference station at the
Ladoke Akintola University of Technology (LAUTECH) GNSS Laboratory logged raw GNSS data, which
were processed to obtain carrier-to-noise density ratio (C/N₀), number of satellites visible, satellite elevation
angles, positional dispersion, and Single Point Positioning (SPP). Accuracy metrics were used to evaluate
the position solution. Results show that Galileo E5 provides the highest and most stable C/N₀ (≈41–42 dBHz), while all signals exhibit a systematic midday C/N₀ dip around 13:00–15:00 UTC, identifying a
vulnerability window for critical operations. GPS offers more stable satellite visibility and consistently
lower standard deviations in latitude, longitude, and altitude than Galileo, whereas Galileo maintains higher
mean elevation angles. The GPS+Galileo hybrid solution delivers the best overall performance, improving
SPP accuracy by approximately 8–11% relative to GPS-only and up to 50% compared with Galileo-only,
depending on the metric. The findings support prioritising hybrid GPS+Galileo operation and time-aware
mission planning to enhance positioning reliability in equatorial low-latitude regions