Abstract
In order to realize an accurate and robust positioning system, the precise trajectory estimation is necessary. GPS-Doppler, which can estimate accurate vehicle heading, is one of the most effective approaches to the precise trajectory estimation. However in urban areas, where only a few satellites can be observed, the heading estimation using GPS-Doppler can’t work as it does in suburban areas. In this paper, time-series GPS-Doppler and INS (Inertial Navigation System) are tightly coupled in order to improve robustness in urban areas. With the proposed method, the error of heading estimation has been reduced and the trajectory estimation has been improved in urban areas.