New imaging condition of elastic reverse-time migration for converted waves

Abstract

In this study, we address the polarity reversals in P-S and S-P images and non-physical events generated in S-P and S-S images from ERTM with the conventional zero-lag crosscorrelation. To overcome these problems, we suggest a novel converted wave imaging condition motivated by the specific feature of ERTM that can generate converted waves at the image points when proper elastic models are used. Comparisons with the zero-lag crosscorrelation imaging condition demonstrate that ERTM with our proposed imaging condition can compensate polarity reversals as well as suppress spurious events and even provides the improvement of imaging resolution.