In a Global Navigation Satellite System (GNSS) the distance from (at least) 4 satellite vehicles needs to be measured by a receiver to obtain an estimate of its position. This information is extracted from signals transmitted by satellites, but GNSS services can fail or lose reliability when propagation is not in Line-of-Sight (LOS) conditions. In this sense, an urban scenario represents a harsh environment where obstacles may obstruct the satellites view. As a result, limited availability and lack of continuity commonly arise.The rise of smart transport paradigm, and the development of Intelligent Transport Systems (ITS), is nowadays a task of interest for the GNSS community, since it is related to precise and reliable positioning systems.