The multi-constellation SBAS-R interface as an international standard for high-safety integrity land transport systems

During two last decades satellite navigation (GNSS) demonstrated its advantages besides aviation and maritime also in numerous non-safety applications in different land transport sectors. Nevertheless it is expected that “the golden age” of GNSS in land transport will come as lately as high-safety integrity and dependability of integrated solutions will be demonstrated and the use of GNSS in land safety-related systems will be standardized. In Europe a great effort in this area is currently focused on use of EGNSS, which includes two main systems - EGNOS, which belongs to the SBAS family, and Galileo. This paper deals with a new safety concept of the multi-constellation EGNOS-R interface which was originally proposed to meet the highest Safety Integrity Level (SIL 4) for the EGNOS Signal-In-Space, as it is required by the European Train Control System (ETCS). Fundamental benefits of EGNOS-R are summarised. A great potential of the EGNOS-R concept is further demonstrated using a new innovative method for excessive multipath error detection and identification, and also via protection of user against correlated excessive pseudorange errors. Since the EGNOS-R concept can be easily transferable to other non-European regions where similar regional multi-constellation augmentations from the SBAS family are or will be available, the international standardization of the EGNOS-R concept via a more general SBAS-R standard for SBAS exploitation in land safety-related systems is proposed. This new international SBAS standard can significantly support export of advanced EU technologies (e.g. ETCS) and thus justify the use of EGNSS on markets out of Europe.