GPR multi-component data analysis

In order to test the capabilities of ground-penetrating radar (GPR) detection, models were reproduced in a laboratory using both plastic and metal cylinders as well as sheets to represent anomalies buried in a plastic tank containing sand. These models, which represent pipes and dipping layers in a homogeneous medium (i.e., sand), were used to detect the object’s position and study its polarization properties based on the different dielectric contrasts between the object and the surrounding medium. We paid particular attention to the choice of medium through which the wavefield propagated, to be sure of its isotropy and homogeneity, in order for the velocity to be the same for every path travelled. Experimental tests were carried out by changing the dielectric contrasts from the target to the surrounding medium. In particular, the dielectric cylinders (which have a lower permittivity than that of the surrounding sand) were filled with different substances to represent targets such as PVC pipes, either empty or filled with hydrocarbons or water. The resulting scattered field depended on the electrical properties of both the cylinder and the surrounding material, the distance from the cylinder and the scattering angle. Further experimental tests were carried out by using multi-component GPR data to study the possibility of calculating the angle between the direction of the profile and that of the anomalies. The experimental data obtained as responses to the physical models proved that this method can be successfully applied to detect the orientation of dipping layers, cylinders and vertical fractures.