Interferometric prediction and subtraction of surface waves with a nonlinear local filter

摘要

Surface waves are a form of coherent noise that can ob_scure valuable reflection information in exploration records. It is sometimes difficult to eliminate these surface waves by traditional filtering approaches, such as an f-k filter, without damaging the useful signals. As a partial remedy, we propose an interferometric method to predict and subtract surface waves in seismic data. The removal of surface waves by the proposed interferometric method consists of three steps: (1) remove most of the surface waves by a nonlinear local filter; (2) predict the residual surface waves by the interferometric method; (3) separate the residual surface waves from the re_sult of step 2 by a nonlinear local filter, and remove the resid_ual surface waves by a matched filter from the result of step 1. Field data tests for 2D and 3D data show that the method ef_fectively suppresses surface waves and preserves the reflec_tion information. Results suggest that the effectiveness of this method is sensitive to the parameter selection of the nonlin_ear local filter.