title: Adaptive finite difference for seismic wavefield modelling in acoustic media.
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.
authors.affiliation: Department of Earth Science and Engineering, Imperial College London, London SW7 2BP, UK.
authors.forename: Gang
authors.initials: G
authors.lastname: Yao
authors.affiliation: The Unconventional Natural Gas Institute, China University of Petroleum (Beijing), Beijing 102249, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Earth Science and Engineering, Imperial College London, London SW7 2BP, UK.
authors.forename: Henry Alexander
authors.initials: HA
authors.lastname: Debens