Poliak, J.; Hänsel, F.; Marais, J.:
Validation process for usage GALILEO in railways.
Proceedings of the 15th International Symposium Eurnex - Zel 2007 "Towards the competetive rail system in Europe", Zilina/Slovak Republic, May 2007.


Satellite-based positioning systems are promising solutions for the future of railways as they can satisfy most of the requirements they are not depending of national systems and they can be embedded solutions instead of infrastructure equipments and thus reduce maintenance costs. The main challenge for a good penetration of the domain will be to prove that performance answer to railway requirements in real railway conditions of use in particular for safety related applications especially on low density secondary lines.

The paper will offer an overview of railway requirements for positioning and Galileo specifications. Both communities are using their own definitions and their own language. The aim of the first part of the paper will be to compare them. Moreover, in order to help them to understand themselves and make railways accept Galileo as a reliable system, we will describe the two certifications usages.

The second part of the paper will concentrate on the proposal of a methodology in order to validate the GALILEO performance in a real railway environment. The work to perform will be written in the context of the already existing GALILEO certification process. From the railway point of view, a GALILEO receiver will be used as certified equipment. However the reception conditions, that impact on positioning accuracy or availability, will be studied in typical railway environments. These typical environments will have to be defined and described. This work will combine the PREDISSAT tool developed at INRETS that analyses reception conditions extracted from a video record along lines and the iVA tool, CaRail that allows us to compare measurements to an experimental reference platform. The use of both tools will give some important information for precise performance analyses. This work will be performed in close contact with railway managers via the UIC working group. Their support is mandatory to propose clear answers and scenarios as close as possible from the real conditions of use. The certification process will have to be answered and explained in order to convince users and find a common language between the two communities, part of a common chain.