An analysis of the effects of multipath signals due to reflections from the Earth's surface for the Navstar Global Positioning System (GPS) is developed. Ground multipath is modeled in this paper by considering the Earth's surface to be composed of a dielectric slab of soil on top of a perfect conductor. Two multipath signals are considered using this model. The relative time-phase delays and the relative amplitudes of the two multipath signals with respect to the direct ray are analyzed in both dry soil and wet soil. In addition the states of polarization of the two multipath signals are examined.
Finally, software is developed to characterize the multipath error on a C/A-code tracking loop. It was determined that the analysis of ground multipath according to image theory provides accurate results in wet soil but not necessarily so in dry soil.