Velocity model based diffraction filtering

Diffracted wav es hav e been recognized as carriers of important information on small scale structural details in the earth, such as faults, pinch-outs and small scattering objects. In order to avoid any distortion of this information during a stacking process, it is profitable to isolate and analyze diffractions in the prestack shot domain, using all available knowledge of the depth model. Diffraction analysis in the prestack domain has also the advantage that models of arbitrary complexity are allowed and that it can be linked to full prestack depth imaging. Diffractions can be filtered out in common shot gathers by means of a directional median moving window filter, which operates along traveltime curves, defined by Green's functions in the depth model.