Vector elastic least-squares reverse-time migration for reflectivity imaging

We introduce a practical vector operator of reflection demigration of PP and PS waves, and develop a vector elastic least-squares reverse-time migration (LSRTM) method for PP and PS reflectivity imaging. The time-domain demigration operator and the vector elastic reverse-time migration (RTM) operator with the inner dot-product imaging condition are approximately considered to be the adjoint of each other. Our inversion-imaging method is robust and practical, because it does not involve any phase or amplitude correction for source, adjoint, or demigration wavefields, and performs well with only kinematically accurate migration velocity models. We demonstrate the efficacy and advantages of our vector elastic LSRTM method using synthetic and field data. Our method successfully improves PP and PS images with enhanced spatial resolution and balanced image amplitudes using only a few iterations.