Coherent noise attenuation in GPR data by linear and parabolic Radon Transform techniques

Abstract

Ground Penetrating Radar (GPR) is a geophysical method increasingly used in numerous shallow applications. Unfortunately, electronic or acquisition problems can cause the presence in the radargrams of coherent noise interfering with the useful signal. A commonly observed phenomenon, especially for not-shielded antennae, is the surface-scattering effect, due to reflection or diffraction from above-surface objects. These noise events appear with a characteristic hyperbolic moveout in the usual common-offset sections. Other frequent problems are related to the presence of horizontal or dipping features due to system-ringing or other non-geological causes. Several methods have been tried to overcome these problems, most of which involve time domain or Fourier domain filtering. This work presents an attempt to reduce some of these noise modes by an original adaptation of filtering techniques implemented in the Radon domain. The Radon Transform (RT), both in the linear (or t-p) and in the parabolic version (or t-q), has been widely used in seismic processing, especially for multiple removal, but is still quite unfamiliar to GPR practitioners. The results achieved by different RT based methods for coherent noise attenuation in a GPR field example, compared to those of more conventional techniques, are quite encouraging.