The purpose of this study is improving accuracy of the GPS receiver as a vehicle trajectory sensor equipped with a GPS Guided Vehicle. We examined accuracy of the measured data of the GPS receiver by fixed point stand alone measurement, and apply the Kalman filter to the actual measured data. Then, improvement of accuracy, which is from 1.86mCEP to 0.69mCEP, of the measured data was found. Because of a GPS Guided Vehicle move and considering pursuit of vehicle dynamics, there could be said that time-varying Kalman filter, which consider varying process noise and sensor noise at all time, has been appropriate for a GPS Guided Vehicle.
