Scattered noise suppression based on the double-focusing method

When seismic waves propagate through the highly heterogeneous shallow layers, multiple orders of scattering waves will be developed along the wave paths, leading to a very complex wave pattern on the reflection data received by the geophones on the surface. The scattered noise exhibits a non-uniform pattern on the shot gathers from the near to far offset over recording time. The frequency content of the scattered waves typically span over the entire frequency band, greatly compromising the quality of seismic data. In desert regions, the serious heterogeneity of near surface sand layers contributes great much to the severity of the scattering noise, posing substantial challenges to the processing and imaging of seismic data. In this paper, Marchenko's method is employed to reconstruct the seismic source and detector positions underneath the heterogeneous geological formations, effectively mitigating the impact of scattered noise to the final image. Numerical experiments demonstrate successful seismic wave redatuming beneath the scattering layers, leading to scattering noise suppressed shot data on the redatum surface. The noise suppressed data hence result in a much cleaner final migration image.