This paper makes an analysis of the quantitative correspondence between the GPR-TDR and GPR-gravimetric measurements of moisture content.The data were obtained from laboratory and field experiments. In the laboratory test, the vadose zone was simulated by injecting and draining water in a sand tank. The experiment was conducted with 1 GHz antennas. The in situ test was carried out on unsaturated residual soils, in an area susceptible to landslide, with 200 MHz antennas. To measure soil water content with GPR, we used the velocity of ground wave, refracted and reflected waves. The GPR response was sensitive to changes in subsurface moisture in both experiments and showed good correspondence with TDR (RMS error of 0.007 m³m-3) and gravimetric (RMS error of 0.039 m³m-3) measurements.
GPR; TDR; moisture content; dielectric constant
