SVD filtering applied to ground-roll attenuation

Abstract

We present a singular value decomposition (SVD) filtering method for attenuation of the ground roll. Before the SVD computation, normal move-out (NMO) correction is applied to the seismograms, with the purpose of flattening the reflections. SVD is performed on a small number of traces in a sliding window. The output trace is the central trace of the first few eigenimages. These contain mostly horizontally aligned signals, and other noise in the data will be suppressed. By performing this action with the sliding window moving in steps of one trace, the number of output traces is equal to the number of input traces. The new method preserves the character and frequency content of the horizontal reflections and attenuates all other type of events. We illustrate the method using land seismic data of the Tacutu basin, located in the northeast part of Brazil. The results show that the proposed method is effective and is able to reveal reflections masked by the ground roll. The new SVD filtering approach provides the results of better quality, when compared with the results obtained from the conventional f-k filtering method.