An application of the synthetic emitter-array method to improve GPR signals

Methods that employ arrays of emitters are potentially useful in improving weak or ambiguous signals in ground penetrating radar (GPR) prospecting. As in the seismic case, the electromagnetic responses from the subsurface can be obtained by employing true composite sources or synthesized from single emitter responses that are acquired with variable offset, both possibilities leading to similar results. In this article, the synthetic emitter-array method is examined as a way of improving GPR signals. Modeling of transmitted wave-fronts is carried out to analyze how the targets can be illuminated so that the reflected signals are effectively reinforced. The method is applied to different targets. A methodology that simultaneously increases the signal to noise ratio and the lateral coherence of the events is examined in order to facilitate the interpretation of the GPR data. Finally, the synthetic emitter-array method is successfully applied in a case study to determine the width and depth of mud walls at the Palo Blanco archaeological site in Argentina.