Mitigation of Static Carrier-Phase Multipath Effects Using Multiple Closely Spaced Antennas

Abstract

ABSTRACT: The effect of carrier-phase multipath on static GPS applications is investigated, and a system for reducing the effect using multiple closely spaced antennas is developed. The correlated nature of multipath and the known geometry among the antennas are used to estimate and mitigate carrier-phase multipath. The mathematical model of the multipath effects on carrier-phase measurements and the Kalman filter implemented to estimate these errors are described. The model is first tested on simulated data and later on field data collected on a roof, where the model adaptively estimates the parameters of the composite multipath signal. Initial results show that the root-mean-square value of the average multipath error on single-differenced carrier-phase measurement data is typically reduced by over 70 percent.