Abstract
In recent years, the global positioning system (GPS) has been extensively used in the daily life. The most common application is a vehicular positioning device for planning and navigating the destination and promoting traffic safety. However, GPS has an error of about 10-15 meters without using calibration. The positioning errors are caused by signal arrival time errors, atmospherics effects, ephemeris errors, multipath errors, and other effects. The present calibration systems can reduce the position errors to 3-5 meters. But the systems have to set up the reference stations, the master stations, or the GEO satellites. In this thesis, we proposed a reference-station-free calibration method to calibrate the GPS position using cooperative vehicles. We experiment our calibration method using the realistic GPS data. The results show that the calibration method can improve the accuracy performance of GPS positioning notably.