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Acoustic Wave Modelling in Frequency Domain with Irregular Topography
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 79th EAGE Conference and Exhibition 2017, Jun 2017, Volume 2017, p.1 - 5
Abstract
The computation of acoustic wave equation is the fundamental kernel of seismic imaging and waveform inversion. Forwarding modelling from finite-difference (FD) method in frequency domain is particularly useful because of its computational efficiency in multisource experiments and flexible grid spacing selection. However, it suffers from the difficulty of handling the seismic data acquired on irregular topography. To apply the FD method in frequency domain (FDFD) on irregular geometry, we propose to calculate the wavefield in topographic coordinate meshes. Using the mapping relationship from conventional Cartesian coordinate system to the topographic coordinate system, the wavefield is simulated with high accuracy when the geometry exhibits irregular surface. The perfect match layer (PML) and the grid dispersion for the defined topographic coordinate in frequency domain are discussed. We use a uniform model and resampled Foothills model to illustrate the basic workflow and demonstrate the efficiency of our approach. This method has the potential ability to be the forward modelling solver when seismic imaging and waveform inversion in frequency domain encounter complex surface scenarios.