Finite-Difference Contrast Source Inversion Method for Elastic Wave Equation

Summary This abstract extends the finite-difference contrast source inversion (FD-CSI) method to reconstruct the P-wave and S-wave velocity for two-dimensional elastic wave inversion in the framework of the full-waveform inversion. The FD-CSI method is an iterative nonlinear inversion method, which exhibits several strengths. First, the finite-difference operator only relies on the background media and the given frequency, both of which are unchanged during inversion. Therefore, the full forward problem is required to be solved only once at the beginning of the inversion process, which makes the method very computationally efficient and ideal for large-scale 3D inversion calculations. Another attractive feature of the inversion method is that it is with strong capability in dealing with nonlinear inverse problems in an inhomogeneous background medium, because a 25 points finite-difference operator is used to represent the differential operator governing the two-dimensional elastic wave propagation. Numerical reconstruction results show that the inversion method has an excellent performance for reconstructing P-wave and S-wave and can provide more accurate velocity information for seismic data processing and interpretation.