Multiscale Phase Inversion for Vertical Transverse Isotropic Media

In anisotropy full waveform inversion (FWI), the pseudo-acoustic approximation is widely used to reduce the computation cost. However, artifacts and inaccurate predictions of amplitudes by the pseudo-acoustic approximation often result in slow convergence in the FWI iterations and inaccurate tomograms. To solve this problem, multiscale phase inversion (MPhI) methodology is extended to vertical transverse isotropic (VTI) media. In MPhI, the amplitude spectra of the predicted data are replaced by those of the recorded data to mitigate the amplitude mismatch problem. Moreover, MPhI tends to avoid the local minimum problem of full waveform inversion (FWI) by temporally integrating the traces several times. Numerical tests on synthetic data and field data demonstrate the superiority of this method compared to conventional multiscale full waveform inversion for VTI media.