GNSS Introduction in the RAIL sector

GRAIL is an FP6 project initially managed by the Galileo Joint Undertaking (GJU), but this year being managed by the GNSS Supervisory Authority (GSA) that has taken over from the GJU. The title of the project, GNSS for RAIL, addresses the use of GNSS in all rail applications. However, the number of railway applications where GNSS could be used is very large and so the focus of the project is on Safety-Critical applications and specifically on ETCS (European Train Control System), although other applications (like Asset Management, etc.) are also investigated. The first ETCS application to be addressed in the project is the use of GNSS in enhanced odometry. In this configuration, GNSS-based location is used as substitute or complement to the current odometry sensors (tachometers, INS, Doppler Radar etc.). It can, therefore, remain internal to the ETCS (as a part of the Odometry Macrofunction). In this configuration the GNSS system is composed only of a GNSS receiver, augmented, if needed, by local elements to achieve the required performances (in safety, for example). The expected improvements of this approach for ETCS are the overall improvement of Train Location accuracy and a reduction in safety margins and tolerances. The presentation will address the common specifications agreed in GRAIL by all signalling suppliers and under review by ETCS rail operators, as well as the future trials in Spain.