Prospecting an archaeological site by GPR. The case study of the buried necropolis Laurentina

Nowadays the use of Ground Penetrating Radar (GPR) in archaeology has spread widely, indicating this method to be an effective means of detection and mapping of buried remains. However, some limitations have been reported by researchers and users, mainly related to the low resolution or penetration depth of the electromagnetic (EM) signal, especially in highly dispersive soils. In such a context, a robust and data adaptive processing scheme may increase the reliability of the interpretation of the GPR data. This work reports on a case study concerning a preliminary geophysical survey at an archaeological site with interest in the presence of a buried roman necropolis. The tests have been carried out by means of a ground-coupled dual-frequency GPR system, over a rectangular area defined by a regular grid with 1 m spacing interval between each scan line. A specific processing protocol has been applied to the collected dataset in order to maximize the interpretability of both the radargrams and the extracted depth slices. As a result, the analysis allowed to recognize two areas dominated by regular flooring whereas, at shallower levels, it permitted to detect a pattern of walls.