Poststack Depth Migration Velocity Analysis Using Residual Diffraction Moveout

DEDICATED - Case Studies in Diffraction Imaging and Interpretation" Diffraction events contain direct information on the medium velocity. In this work, we develop a method for migration velocity improvement and diffraction localization based on a moveout analysis of over or undermigrated diffraction events in the depth domain. The method uses an arbitrary initial velocity model as input. It provides an average velocity model and diffraction locations in the depth domain as a result. The algorithm is based on the focusing of remigration velocity rays from incorrectly migrated diffraction curves. These velocity rays are constructed from a ray-tracing like approach applied to the image-wave equation for velocity continuation. After picking the diffraction events in the migrated domain, the method has a very low computational cost, and the diffraction points are located automatically. We demonstrate the feasibility of our methods using one synthetic data example.