Review of multi-offset GPR applications: Data acquisition, processing and analysis

GPR and reflection seismics share common physical and methodological bases but are sensitive to different subsurface physical properties. The peculiarities of the electromagnetic case impact data acquisition, processing and interpretation. We review multi-offset techniques in GPR applications focusing on similarities and differences through examples taken from different subsurface and target conditions. GPR multi-offset data acquisition methods basically involve common-offset and common midpoint geometries: accuracy and work load are the main factors that drive the choice, together with effectiveness of the solution for the objectives of the study. Multi fold data processing algorithms can bring remarkable signal-to-noise ratio enhancement and offer the opportunity to extract additional information from field data. Velocity field and related dielectric constants distribution, attenuation and related conductivity variations, changes in the GPR response with offset are some of the examples. Coherent noise suppression and velocity analysis are key features in GPR multi fold processing sequences and we review the relevant methods with examples of application in addition to technical aspects. Multi-channel acquisitions, full wave-form inversion, pre-stack depth migration, azimuthal and polarimetric analysis, are among the many topics in current and future research that are briefly reviewed to provide some highlights of the forthcoming developments in GPR methods.