Removal of Guided Waves From Seismic Data in Laterally Varying Media

A major source of unwanted signals in seismic data recorded for geophysical exploration is the presence of guided waves which are scattered near the surface of the earth. These waves do not contain information on the structure of the deeper subsurface and should therefore be removed. In this paper we derive a method for removing this type of waves based on a modal expansion. The problem of finding an appropriate scatterer distribution is formulated as a minimization problem. We apply the method to simulated data and watertank data, and find that the scattered guided waves are strongly attenuated and that the reflections of interest (from deeper layers) are not affected. 1 Introduction In geophysical exploration, one tries to obtain an image of the subsurface by exciting a wavefield, and recording the reflections from the earth by receivers located at the surface. The regions of interest for geophysical exploration are the deeper ones. Nevertheless, the strongest signals in the data ar..