Internal multiple elimination by an extended 3D single-sided autofocusing and the application to subsalt imaging

Summary We propose an extended 3D single-sided autofocusing guided by inverse-scattering theory for internal multiple elimination. Internal multiple modelling and elimination is formulated as an equivalent-scattering source imaging problem with limited-aperture. In our derivation, the focusing source is obtained by a cumulative TRM (time-reversal mirror) autofocusing process. The extension of TRM process is guided by inverse-scattering theory, and is based on causality, energy conservation and source-receiver reciprocity. From this derivation, the application range of internal multiple elimination can be expanded to complex interfaces and irregular-shaped inclusions. Numerical examples of salt-multiples removal and subsalt imaging proved the broad application range of the theory and method.