Satellite Propagation Analysis in a Masking Environment for GNSS Applications

Most of the applications for localization and navigation in the field of transport use satellite systems (such as GPS, GLONASS, or the future European GALILEO system). With the launch of the European Galileo constellation, a new generation of satellite navigation system is envisaged. The key challenges for the development of new applications concern accuracy, availability and integrity of the positioning service that are not always guaranteed in transport environments. The PREDISSAT tool, developed at INRETS in order to predict satellite availability in a known environment, is presented. Both PREDISSAT and the ray-tracing tool ERGOSPACE have been used to produce different results: availability study along a railway line, propagation channel modeling, analysis of the positioning performance in a modeled environment. From this environment knowledge, new rules able to increase the navigation performance based on satellite only may be derived. The goal is to enhance as much as possible the use of GNSS alone for new and enlarge localization or localized based services for buses in a first step. This new technique will be extended to other transport modes. For the covering abstract please see ITRD E135207.