Assessing the Quality of Products and Latest Performance of Galileo HAS (High Accuracy Service) Using Real-Time Data

The Galileo High Accuracy Service (HAS) offers free, real-time precise point positioning (PPP) corrections via Galileo (E6-B) and internet, supporting Galileo (E1, E5a, E5b, E6) and GPS (L1, L5) signals. As of Service Level 1, HAS provides SSR orbit, clock corrections, and biases, achieving decimeter-level accuracy (20 cm horizontal, 40 cm vertical) within 300 s (95th percntile), per the HAS ICD. This study compares HAS products with other analysis centers, verifying declared accuracy. Using a Septentrio Mosaic X5 GNSS receiver, real-time HAS data was collected over three weeks, verified against CODE products, and assessed for PPP performance under various scenarios to evaluate HAS reliability for high-accuracy positioning. The analysis has shown that HAS products provide superior accuracy for Galileo (9.6 cm URE) over GPS (14.0 cm URE) and enable decimeter-level positioning convergence within 3–5 min, although significant outliers were detected in the GPS clock corrections.