Prestacking migration by spilt-step DSR

Abstract

Abstract The double-square-root (DSR) prestack migration equation, though defined for depth variable velocity, can be used to image media with strong velocity variations using a phase-shift plus interpolation (PSPI) or split-step correction. The split-step method is based on applying a phase-shift correction to the extrapolated wavefield--a correction that attempts to compensate for the lateral velocity variations. I show how to extend DSR prestack migration to lateral velocity media and exemplify the method by applying the new algorithm to the Marmousi data set. The split-step DSR migration is very fast and offers excellent imaging results.