Dip selective 2-D multiple attenuation in the plane-wave domain

In many geological settings, strong reflections at the air-water interface contribute to most of the multiple energy in the recorded seismograms. Here, we describe a method for free-surface multiple attenuation using a reflection operator model of a seismic record, derived using the well-known invariant embedding technique. We implement this method in the 2-D plane-wave domain, where lateral-variation of the geological structure of the earth is taken into account by the coupling of different ray parameters. In situations where the lateral variations are smooth, the data are well compressed in the 2-D plane-wave domain and the resultant bandlimited matrices significantly reduce the computation cost. One important feature of the proposed method is its flexibility, which allows for the removal of multiples from selected reflections. To generate multiple free data, wave-theory-based multiple attenuation methods attempt to estimate either the source function or the subsurface reflectivity. Our method takes advantage of both approaches, such that we initially predict multiple traveltime using the reflectivity approach and then seek a source function to predict the amplitudes. Synthetic and real data examples show that this method is stable and successful in attenuating the surface multiples.