High-Accuracy Point Positioning with Low-Cost GPS Receivers

Abstract

: Dual-frequency, geodetic-quality GPS receivers are routinely used both in static and kinematic applications for high-accuracy point positioning. However, use of low-cost, single-frequency GPS receivers in similar applications creates a significant challenge because of how the measurement error sources are handled. In this paper, we examine the potential use of such receivers to provide horizontal positioning accuracies of a few decimetres. Applications include a myriad of terrestrial and space-borne applications, where the size, power consumption, and cost of the GPS unit is an issue. Our processing technique uses pseudorange and time-differenced carrier-phase measurements in a sequential least-squares filter. The technique was first tested on L1 measurements extracted from static, high-quality GPS receiver datasets. Accuracies better than two decimeters in horizontal components (northing and easting r.m.s.), and three decimeters in the vertical component (r.m.s.), were obtained. Horizontal positioning accuracies obtained from a low-cost receiver were within the few decimeter level.