Abstract
This paper proposes a technique of position estimation which is applicable to urban environments where the accuracy of GPS positioning is deteriorating. The method, utilizing GPS Doppler processing and gyros, calculates trajectories by extracting the most reliable azimuth, which is then integrated with vehicle speed. Our approach focuses on integrating these segments of the trajectory with GPS pseudoranges which are received at points throughout the whole trajectory. Using the pseudoranges obtained in the past, it is possible to judge the confidence level of these results. This makes it possible to select the best satellites for positioning. An evaluation test on a road course passing by high-rise buildings and under overpasses in a city area showed that our proposed method achieves more accurate position estimation than conventional methods, demonstrating its effectiveness.
Keywords: ITS, GPS, Positioning