A Novel GNSS Positioning Technique for Improved Accuracy in Urban Canyon Scenarios using 3D City Model

Reliable positioning in urban canyon, especially in dense urban areas, is difficult to achieve in a cost-effective manner using standalone Global Navigation Satellite System (GNSS), due to multipath problems and Non-Line-of-Sight (NLOS) signals. In this regard, several researches have focused towards identifying and rejecting NLOS measurements. However, very few researches have used NLOS signals, although generating final position using only one of the signals. In this regard, this research utilizes all the available signals, including all NLOS signals, from all the satellites, in order to estimate position, using an algorithm based on concept of constructive use of NLOS signals. The NLOS signals are used constructively by incorporating the information related to nearby reflectors, with the help of a 3D city model. The feasibility and performance of the algorithm was done using a real data collected in Downtown Calgary. In a way, this research attempts towards building a low cost GNSS based technology for improved navigation performance, in scenarios where fewer satellites are available and rejecting measurements due to blunders might cost a crucial stake of availability.