Elastic and Viscoelastic Full-Waveform Inversion
Elastic and Viscoelastic Full-Waveform Inversion: This chapter presents the theory of elastic and viscoelastic full-waveform inversion (FWI), which, in principle, reconstructs both the P- and S-wave velocities from the seismic data. Instead of modeling the acoustic wave equation, the modeling and back projection of the data use numerical solutions to either the elastic or viscoelastic wave equations. To account for attenuation, the viscoelastic wave equation is used both to forward propagate and back propagate the wavefields. This means that estimates of the P-wave attenuation QP and S-wave attenuation QS distributions are needed as input information into the viscoelastic modeling code. These distributions can be estimated by a ray-based inversion scheme or a wave-equation inversion scheme.