From pseudo-3D to full-resolution GPR imaging of a complex Roman site

This case history demonstrates how an extra effort applied to data acquisition can benefit the interpretation of 3D GPR data over a Roman site of great complexity situated in a semi-urban area. Two surveys (during May 2007 and July 2008) were accomplished after Roman wall remains had been found, by chance, during soil removal work at Agro da Ponte (Lugo, NW Spain). The same 250 MHz antenna was used for both of them. The first campaign covered the entire area using a pseudo-3D strategy (GPR lines spaced by 0.5 m), which was only enough for defining areas of interest and some archaeological features. Based on these results, the next campaign focused on a smaller area and was based on an ultra-dense grid strategy (GPR lines spaced by 0.1 m), which eventually revealed full-resolution images of walls, apses and chambers of a Roman villa.