Elastic Reverse Time Migration Based on Decoupled Wave Equation and Inner Product Imaging Condition

In conventional elastic reverse time migration, Helmholtz Decomposition is applied for wavefield separation, which leads to polarity reversal in converted wave imaging. In this paper, we introduce a vector wavefields separation method with amplitude preserved based on decoupled elastic wave equation and illuminate the specific physical meaning of the vector P- and S-wave. In addition, the inner product imaging condition is utilized to obtain image results form the vector P- and S-wavefield. Analysis of imaging kernel indicates that the presented method can effectively circumvent polarity reversal in ground seismic exploration. Migration results have demonstrated the feasibility and effectiveness of this imaging method.