Fig. 1

Geographical framing of the case study (a): Grumentum in the Basilicata Region (Southern Italy); (b) the investigated area. The acquisition direction for MAG and GPR is from NE to SE, x(m) while the acquisition progress is in NW direction y(m). Detailed outline of the GPR data acquisition scheme is in Fig. 2. Orthoimage in (b) provided by Regione Basilicata, Ortofoto 2013, available via WMS: http://rsdi.regione.basilicata.it/rbgeoserver2016/maps_orto2013/OI.OrthoimageCoverage/wms. License: IODL 2.0 (https://www.dati.gov.it/content/italian-open-data-license-v20). Image created with QGIS (QGIS.org, 2024): QGIS Geographic Information System (Version 3.34.3). QGIS Association. http://www.qgis.org.