2D-SEA methodology for GPR reflections

BULLO, DARÍO; BONOMO, NÉSTOR; OSELLA, ANA

Malmö

Congreso; Near Surface Geoscience 2017; 2017

EAGE

TheGPR reflection methodology is frequently used in different areas ofinvestigation, as geology, hydrology, civil engineering and archeology.Depending on the characteristics of the media in which the electromagneticwaves propagate, it can occur that the reflections of interest (normally,primary reflections) present low amplitude with respect to the surroundingclutter and noise in the resulting images, which limits the detectioncapability of the method and the certainty of the interpretations. Then, toovercome these limitations, it is important to design or implement appropriateacquisition and processing techniques that increase the quality of the primaryreflections with respect to the other types of surrounding signals (e.g., Bulloet al, 2016). Usingarrays of emitters and receivers is a way of improving the reflections ofinterest with respect to unwanted signals. This result is mainly attained byadequately superposing the individual waves or records of the array components,so that their amplitudes sum coherently for the reflection of interest andincoherently for the unwanted events. In particular, we have investigatedemploying the Synthetic Emitter Array (1D-SEA) method to improve weak anddiscontinuous reflections, and proposed a general processing methodology thatimproves the GPR results for reflections of arbitrary shapes, i.e., elongatedreflections, small diffractions and compositions of them (Cedrina et al. 2011).By adjusting the distances between the emitters and their relative phases,adequate focalization and orientation of the synthesized fields is obtained,which increases the amplitude of the primary reflections with respect to thesurrounding signals and improves their continuity. As a generalization of thismethodology, we expect that using 2D arrays of emitters, instead of 1D arrays,could further improve the SEA results, since the synthesized fields can beoptimized in both orthogonal directions.  Inthis work, we extend the previously developed 1D-SEA methodology to 2D arrays.We show examples in which the proposed 2D-SEA methodology is applied tosimulated datasets. The results of this methodology are compared to the resultsobtained from the 1D-SEA and the standard Single Offset (SO) methodologies.