Full Waveform Inversion Using Perfectly Reflectionless Subgridding

Abstract

Method for reconstructing subsurface profiles for seismic velocity or other geophysical properties from recorded seismic data. In one embodiment, a starting model of seismic velocity is assumed (10). The computational domain is divided into two (or more) subdomains by horizontal planes based on an analysis of velocity model (30), and the allowed maximum grid size for each subdomain is determined (50). Auxiliary perfectly matched layers (PML's) are attached to each planar interface between subdomains (80), e.g. two PML's on each side of the interface between the coarse and fine subdomains. Simulated seismic data are computed using the SG-DO technique (100-230). The simulated seismic data are compared to the recorded seismic data, then the residual is calculated (240) and used to update the model (320). The method may be iterated until the model is suitably converged (260).

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