Doku tabanlı uydu görünürlüğü algılama

Limited satellite visibility, multipath and non-line-of-sight (NLOS) signals greatly reduce Global Navigation Satellite System (GNSS) positioning accuracy in urban environments. Results of various research have shown that 3D representations of these environments can be helpful for determining NLOS signals and multipath, therefore they can be used to improve positioning accuracy which is invaluable to Intelligent Transportation Systems (ITS) and Vehicular Ad-hoc Network (VANET) applications. State-of-the-art methods use computationally expensive raytracing algorithms on 3D polygon-based maps to determine satellite visibility. In this thesis, we introduce Texture Based Satellite Visibility Detection (TBSVD) method which uses texture-based algorithms to calculate visibility information using height maps of urban structures, contributing to the application of these methods in low-cost receivers and on-board units. Real road tests and measurement campaigns in the business district of the metropolitan city shows that our method, which significantly reduces computational costs and storage requirements compared to raytracing, can be effectively used to improve GNSS positioning accuracy.