Evaluation of the Galileo/GPS High Accuracy Service (HAS) Performance for Enhanced Navigation Precision

Since the Initial Service (IS) declaration on January 24th 2023, the Galileo High Accuracy Service (HAS) is operational and offers free of charge high accuracy satellite-based corrections empowering users globally to achieve real-time positioning accuracy at decimeter-level under nominal conditions. In its full operational capability, Galileo HAS will support 20 cm and 40 cm (95th percentile) horizontally and vertically respectively, within 300 seconds convergence time. CNES, the French Space Agency, is involved in independent Galileo performance assessment activities dating back to the early GIOVE and Galileo launches. Leveraging years of continuous monitoring of Galileo, GPS and SBAS systems, this paper compares and analyses the HAS-enhanced navigation performances of Galileo and GPS systems, providing insightful figures. This paper intent to present a comprehensive analysis of the HAS navigation performance focusing on the availability and accuracy of the corrections, with comparison to reference products. Additionally, the study assesses the accuracy of static opensky positioning obtained through the CNES Precise Point Positioning (PPP) software and examines convergence time. A comparison to the Minimum Performance Levels (MPLs) outlined in the Galileo HAS Service Definition Document (SDD) is also addressed. Findings from this evaluation highlight the enhancement of the Galileo and GPS navigation performances with the addition of HAS corrections. In conclusion, this paper provides valuable insights into the positive impact of the Galileo HAS on navigation precision, establishing it as a pivotal contributor to the evolution of European GNSS capabilities. Keywords: Galileo, GPS, High Accuracy Service, GNSS, Monitoring, Performances, Navigation, Accuracy, Precise Point Positioning