Satellite Visibility and Geometry Analysis for GNSS Positioning in an Urban Environment

Accuracy of urban positioning depends on the quality of signals received by a Global Navigation Satellite System (GNSS) receiver that can be a combination of light of sight, reflection and diffraction signals. The more light of sight signals are received, the more accurate positioning can be achieved. To evaluate signal propagation thus availability of GNSS satellites in urban environments, a ray-tracing based modelling technique is proposed that can predict the light of sight, reflection and diffraction signals together with 3D city model. The developed techniques are validated against in-situ measurements in urban areas with different scenarios.