Satellite propagation path model along a railway track for GNSS applications

The applications of GNSS (Global Navigation Satellite System) services are continuously growing in the field of transport. However, the choice of the system for a given application is directly guided by its availability and the availability of most satellite-based localization processes of terrestrial mobiles is considerably degraded in transport environments because of significant masking effects. In these environments, the availability of positioning information is not always guaranteed. We present the results of a railway study using both experimental measurements and the PREDISSAT simulation tool that we have developed. We follow a Markovian approach with three states corresponding to the three states of reception of the signal (direct, multipath and blocked). The probability of occurrence of each state characterizes the GNSS propagation channel in a railway environment.