Ground-penetrating radar prospection at the Jesuits' Church in Valletta, Malta

In this paper, results of Ground-Penetrating Radar measurements performed at the church of the Jesuits in Valletta, Malta, are presented. This experimental activity was carried out during an International Training School on “Ground-Penetrating Radar for civil engineering and archaeology,” organized by COST Action TU1208 “Civil engineering applications of Ground-Penetrating Radar” and hosted by the University of Malta on January 25-29, 2016. The reported case study is of particular interest, as it shows that the well-known and commonly-adopted method of the diffraction hyperbolas, for the estimation of the propagation velocity from the measured radargrams, is not always reliable. As an alternative, a sequential migration with progressively lower trial propagation velocities was proposed and successfully used. Results presented in this paper include a series of B-Scans and depth slices. Several tombs were detected and located in the subsurface of the main nave of the church