A precise trajectory estimation method using carrier-smoothed GPS for mobile robots

The carrier-smoothed GPS (CSGPS) is a method of estimating a precise trajectory with carrier phase measurements. The integer ambiguities in carrier phase measurements are estimated with code measurements. The CSGPS can be used to provide precise trajectory for high-precision applications. In case of the cooperative simultaneous localization and mapping (CSLAM), localization is effectively accomplished by using CSGPS. However, visibility change of GPS satellite vehicle (SV) in tracking or cycle slips make discontinuity in the trajectory. Therefore, dead reckoning (DR) sensor should be utilized to compensate discontinuities. This paper analyses the performance of CSGPS for an hour without bias compensation. The structure of a loosely coupled Kalman filter that combines CSGPS and DR measurements is also shown.