The impact of spatial sampling and polarisation in GPR survey for utility mapping

The presented analysis has quantitatively evaluated the performance of different GPR survey strategy for the detection and mapping of buried utilities. Results have shown that just the acquisition of a set of sparse 2D profiles is not a reliable strategy, as detection performance drops in presence of complex subsurface geometries, for which the profile spacing might be too wide to properly reconstruct the situation. A step ahead is represented by a 3D survey, in which the increased acquisition effort is balanced by the improvements achieved in terms of reconstruction quality. Targets can be tracked out of the 2D domain, feature that is highly relevant in areas with multiple intersecting objects. However, depolarisation phenomena, critical factor for linear and elongated targets, can be efficiently neutralised by the acquisition and combination of mutually orthogonal GPR volume.