Automatic Shear-wave Velocity Analysis with Elastic Reverse Time Migration

Converted-wave has the potential to be a positive complement of the compressional imaging in some special cases. However, converted wave imaging is more difficult because the need of estimating the background velocity of S-wave. By applying differential semblance to measure the focusing error in the imaging domain, we automatically estimate the background S-wave velocity using reverse-time migration with a given estimated P-wave velocity. Compared to the P-wave, the S-wave velocity estimation via PS imaging gather does not need gradient from the source side. A simple synthetic result demonstrates the feasibility of the proposed method.