A novel method based on GPR signature for identifying and mapping construction techniques concealed beneath plaster in Pompeii

The use of standard non-destructive techniques for investigating the walls of Pompeii’s buildings is often unfeasible due to the substantial thickness of the plaster layers, sometimes reaching up to 9 cm, that conceal the underlying construction techniques. This study presents a novel non-destructive approach based on Ground Penetrating Radar (GPR) for the identification and mapping of Roman masonry techniques. An atlas of GPR signatures is compiled providing an interpretation framework for relating Pompeian construction techniques and GPR data acquired using a dedicated methodology. The proposed method was developed and validated through an extensive and systematic GPR survey conducted on Pompeii’s architectural remains. The results demonstrate that, when characteristic GPR signatures are observable, comparing the acquired GPR profiles with the atlas allows the underlying construction techniques to be identified and mapped with at least a successful rate in 88% of cases, enabling robust and replicable interpretation of radar data.