Track Constrained RTK-like Positioning for Railway Applications

Abstract

Here, we investigate PVT solutions based on multi-constellation receivers and dedicated augmentation networks allowing to determine the track on which a train is operating with a very high safety Integrity level. Because the time needed to accomplish this task has a relevant impact on the rail traffic management performance and, therefore, it is considered a key performance indicator by rail infrastructure managers, a double frequency solution is investigated. Particularly, we focus our attention on the advantages of relative positioning solutions, based on Double-Difference Wide-Laning Carrier Phase measurement combination, exploiting the fact that the train location is completely determined by its mileage due to the track constraint, to speed up track discrimination. No ambiguity fix is required at this scope. Here, a detailed description of the overall processing and achievable performance is given. Performance assessment is provided by means of Monte Carlo simulations based on observations recorded on field campaigns.