Source-Independent Cross-Correlated Elastic Seismic Envelope Inversion for Large-Scale Multiparameter Reconstruction

The elastic full waveform inversion method is a promising way to obtain high-precision underground velocity structures, but it is easily affected by the lack of low-frequency data, the inaccurate source wavelet estimation, and the amplitude errors. The envelope inversion (EI) method can make use of the ultralow-frequency information carried in the envelope of seismic wavefields to construct the large-scale velocity structures of the media. However, currently, no improved EI method can simultaneously overcome the influences of inaccurate source wavelet estimation and amplitude errors on the inversion process. This letter combines the convolved wavefield method, envelope operator, and cross correlation operation to propose a source-independent cross-correlated elastic EI (SICEEI) method. We provide the gradient expression of the new objective function by the adjoint state method. Numerical tests show that the proposed SICEEI method can still obtain reliable large-scale P- and S-wave velocity structures in the case of low frequency missing, inaccurate source wavelet estimation, and amplitude mismatch and has good performances in the moderate noise level.