2D full-wavefield modeling in frequency domain using finite-difference
Zhou Cong1,2, Liu Jiangping2, Luo Yinhe2, Xu Hao2, Ji Lingyun1
1. Second Monitoring Center, China Earthquake Administration, Xi'an, Shaanxi 710054, China;
2. Institute of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China
Abstract:Full-waveform inversion (FWI) including surface wave and body wave in frequency domain is still a challenge because of their different physical behavior and nature. But it would lose of resolution and show artifacts if we neglect the free surface in inversion. Therefore, full-wavefield modeling considering free surface condition in the frequency domain is a fundamental work to solve this problem. Based on frequency domain elastic wave equations, we use perfectly matched layer to attenuate the refection of the artificial boundary, and try to introduce implicit boundary conditions to frequency domain modeling in order to simulate Rayleigh waves, which is usually used as free surface condition in time domain seismic modeling. By using 25-point finite difference method, we perform full-wavefield modeling in the frequency domain. Then, we validate our results by comparing them with elastic wave analytic solutions in homogeneous medium and theoretic phase velocities of Rayleigh wave in layered medium. Finally, we analyze wave propagation in both the frequency domain and the time domain in two layered medium.