High Integrity Multiconstellation Positioning In Ertms On Satellite - Enabling Application Validation

The adoption of the GNSS for the European Rail Train Management System -ERTMS is one of the objectives included into the ERTMS evolution plan to improve its competitiveness on the market. To this aim, in 2015 the European Global Navigation Satellite System Agency (GSA) approved the "ERTMS on SATELLITE -Enabling Application Validation (ERSAT EAV)", project with the object to verify the suitability of GNSS to generate Virtual Balises as an alternative/complement means to the physical balises prescribed by the ERTMS. The architecture of ERSAT EAV based on joint use of multiple constellations and public augmentation networks - would be a contribution to foster cost-effective ERTMS solutions, primarily for the local and regional lines in Europe for which the economical sustainability is a priority. The paper describes the hazard's mitigation techniques affecting the on board GNSS receiver when operating in harsh environments, and the scenarios for a smooth introduction of GNSS into the ERTMS system. Field test results carried out on a Test Bed implemented on a 50km line in Sardinia are presented and discussed.