Track constrained PVT estimation based on the double-difference technique for railway applications

In this paper we investigate the issue of positioning and tracking of a train, supported by pre-existing control and monitor system, as well as the use of satellite positioning services. The use of satellite technology can represent a viable solution to reach the goal of unmanned trains in the next future. Many forecasts consider that in a short future GNSS will meet the CENELEC railway safety standards and then will be fully operative into railway operations. This paper presents a satellite positioning technique, which exploits the double-difference approach, in order to meet the constraint of safety level, as well as track constraint.