Ground‐penetrating radar survey to map the location of buried structures under two churches

The range of ground‐penetrating‐radar (GPR) applications is very wide and diverse. Ground‐penetrating radar provides high‐resolution continuous profiles, and it has been used in various fields such as environmental, geology, geotechnical engineering, archaeology, etc. Two surveys with GPR were undertaken inside two churches (the church of St Oronzo and the church of Immacolata) at Novoli village, located a few kilometres northwest of Lecce (Italy). The purpose of the two surveys was to obtain information about the existence of ancient structures beneath the two churches. No document or writing exists to confirm the presence of structures under the two churches. However, there are several oral testimonies handed down over the centuries that suggest the presence of these ancient structures. Both surveys were carried out using a GSSI Sir System2, incorporating 500 MHz centre frequency antenna. The GPR time slices were constructed from closely spaced parallel profiles. The time slices, computed from averaging radar reflections over vertical time windows several nanoseconds thick, are used to map subsoil features associated with the structures, probably of anthropogenic origin. To facilitate the interpretation of the results, a three‐dimensional image was constructed using closely spaced parallel profiles, which are linearly interpolated.