Abstract
Efficient numerical seismic wavefield modelling is a key component of modern seismic imaging techniques, such as reverse-time migration and full-waveform inversion. Finite difference methods are perhaps the most widely used numerical approach for forward modelling, and here we introduce a novel scheme for implementing finite difference by introducing a time-to-space wavelet mapping. Finite difference coefficients are then computed by minimising the difference between the spatial derivatives of the mapped wavelet and the finite difference operator over all propagation angles. Since the coefficients vary adaptively with different velocities and source wavelet bandwidths, the method is capable to maximise the accuracy of the finite difference operator. Numerical examples demonstrate that this method is superior to standard finite difference methods, while comparable to Zhang’s optimised finite difference scheme.
Highlights
Efficient numerical seismic wavefield modelling is a key component of modern seismic imaging techniques, such as reverse-time migration and full-waveform inversion
Seismic wavefield modelling based on the wave equation has evolved to become an essential component of advanced seismic imaging[1,2,3,4,5] and model building techniques, such as full waveform inversion[6,7,8]
We have presented here an improved method for calculating finite difference coefficients
Summary
Efficient numerical seismic wavefield modelling is a key component of modern seismic imaging techniques, such as reverse-time migration and full-waveform inversion. For standard finite difference based on Taylor series expansion, the higher the frequency is, the stronger the dispersion it suffers To mitigate this numerical dispersion, optimisation strategies are often employed to find improved finite difference coefficients (FDCs) that cover a wider frequency bandwidth and wavenumber range, but with limited errors. One such strategy is to seek optimised FDCs for spatial derivatives that are able to decrease dispersion of the spatial terms and compensate somewhat for dispersion of the temporal terms, thereby reducing the overall dispersion errors[11,12,13,14,15]. In this manner we can hope to exploit the maximum potential of finite difference
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
