Attenuation of GPR waves in soil samples based on reflection measurements

Abstract

We investigated the influence of clay and water content on the geoelectrical and GPR properties of various soil samples. The GPR measurements were analyzed not only regarding wave velocity but also with respect to amplitude decay. The attenuation of the GPR waves is quantified in terms of the quality factor Q that can be determined from a comparison of the amplitudes of the direct and reflected waves. We applied the spectral ratio method known from seismic data processing to determine the Q-factor and confirmed the obtained Q-values by foreward wavelet modeling. The investigated soil samples showed variations in the clay contents of 2–60 % and in the volumetric water content from 0 to 35 %. The corresponding quality factors vary between 5 and 15 for high and low clay and water contents, respectively.