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The principle of operation of GPR is generating and sending an electromagnetic wave into examined soil, rock or other material. This is done by transmitting antenna generates a signal of a specific frequency. Wave passed through the soil is refracted, reflected on the geotechnical borders, when encountering facilities, infrastructure or other inhomogeneities wave is dispersed, called diffraction. Both antennas are connected to the control unit, which manages the generation of the reflected wave and the digital recording. GPR signal is triggered by measuring device mounted on wheels. When moving along the profile control unit stores separate traces of signal, which create cross-section called radarograms.

GPR profiling technique, also called reflexive profiling, is the simplest technique for GPR. It involves analysis of the structure surveyed medium using separate sections, where the location is designed before start of the measurement. Theirs positions are adjusted directly during the GPR acquisition depending on the field`s conditions. Given the fact that during the georadar surveys signal dampens with depth increasing and clay minerals contribute to this phenomenon as well. As a result, the effectiveness of GPR strongly restrict silty clay grounds and saturation of soil water.

GPR mapping is an advanced method of interpretation, where in addition to the classical interpretation GPR profiling, performs an interpolated summary of the many georadar sections. This is very important to determine their geometry to replicate as closely as possible the actual location for each profile in the field. For this purpose it can be used a precision GPS receiver. Usually parallel profiles or mesh of profiles (transverse and longitudinal) are applied for more precise scanning of the medium. The distance between the parallel profiles or the mesh size is chosen individually according to each job.