Horizontal resolution in a non-destructive shallow GPR survey: An experimental evaluation

This paper summarizes various approaches to determine the spatial resolution (SR) in non-destructive ground-penetrating radar (GPR) studies and compares the results obtained in these approaches to experimental data acquired in two different media. In one of the experimental measurements, we used 0.4 mS/m conductivity water, which is a low-attenuating medium. In the other case we used sand. Due to the water content in the sand, we obtained velocities similar to the usual velocities in concrete. Experimental radar data showed two different zones: first, the zone in which the recorded anomalies indicate the presence of more than one target; and second, the zone in which the recorded anomalies are related to the existing targets and the interference effects are minimized. We associate the first zone with the antenna's ability to detect two close targets buried at the same depth, and we associate the second zone with the path of the antenna, which is usually estimated as the first Fresnel zone. All of these estimations were carried out using the nominal frequency of the antennas and the dominant frequency obtained from the spectra of the reflected waves.