For application such as Lane departure warning system (LDWS), Simultaneous localization and mapping (SLAM), trajec-tory accuracy is more important rather than positioning accuracy. When using the Carrier-Smoothed GPS (CSGPS), precise trajectory with position bias can be obtained assuming that cycle slips do not take place and satellite set is unchanged. In order to get precise tra-jectory in real application using CSGPS, the change in position bias should be carefully monitored and compensated. On the other hand, dead reckoning (DR) navigation has an excellent short-term accuracy to provide precise relative position and attitude. However, DR sensor errors are accumulated in the computation. As a result, the position and attitude errors increase exponentially if it is not properly calibrated. If the CSGPS and DR are integrated together, real-time precise trajectory estimation is possible even when cycle slips exist in carrier measurements. This paper presents a CSGPS/DR integration system for two-dimensional precise vehicle trajectory estimation. MEMS gyro, accelerometer, and odometer are used for DR system. Accelerometer is used only at the beginning to find early installation error. By field experiments, performance of the proposed integrated system will be verified.

Keywords: carrier-smoothed GPS, dead reckoning, cycle-slip