GPR and IRT tests in two historical buildings in Gravina in Puglia

Abstract. This paper describes a geophysical investigation conducted into two important churches, namely the Cathedral of Santa Maria Assunta and the Church of Santa Croce, both in Gravina in Puglia (close to Bari, southern Italy). The Church of Santa Croce, now deconsecrated, lies below the cathedral. Therefore, the two churches constitute a unique building body. Moreover, below the Church of Santa Croce there are several crypts, which are only partially known. The prospecting was performed both with a pulsed commercial ground penetrating radar (GPR) system and with a prototypal reconfigurable stepped frequency system. The aim was twofold, namely to gather information about the monument and to test the prototypal system. The GPR measurements have also been integrated with an infrared thermography (IRT) investigation performed on part of the vaulted ceiling in the Church of Santa Croce, in order to confirm or deny a possible interpretation of certain GPR results.