Galileo HAS accuracy and convergence performance results

One year after Galileo High Accuracy Service (HAS) Initial Service declaration by the European Commission, this article present Galileo HAS accuracy and convergence comparative performance assessment between two different user algorithm configurations: static and dynamic. The assessment was conducted with two Galileo HAS User Terminal in parallel fed by the same antenna installation to obtain accuracy and convergence for the same period of time. The Galileo HAS User Terminal is a portable and autonomous device powered by a triple-frequency Galileo and GPS receiver and calculates a single (Galileo) or multi-constellation (Galileo + GPS) Galileo HAS using the Performance Characterization User Algorithm developed for the European Union Agency for the Space Programme (EUSPA). The performance assessment is completed with additional analysis in post-processing using a Precise Point Positioning (PPP) engine implementing the same algorithm than the User Terminal fed with International GNSS Service (IGS) stations observables and HAS Internet Data Distribution (IDD) corrections. The analysis is enhanced with an additional postprocessing analysis using the same IGS stations and CNES corrections.

Results for static conditions, assuming zero velocity in the Kalman filter, deliver accuracy performance at decimeter level 68% both horizontal and vertical. Results with the dynamic configuration, with a Kalman filter adaptable to changes in user velocity and fit for dynamic applications, indicate slightly over one decimeter 68% both horizontal and vertical. This article also compares both static and dynamic results vs. the Galileo HAS Service Definition Document (SDD) Appendix E typical positioning accuracy performance and presents the convergence time, or time to first precise fix, against positioning horizontal and vertical thresholds.