3D POST-STACK ONE-WAY MIGRATION USING CURVELETS

摘要

The classical one-way approximation extrapolates the wavefield from the surface. At each depth level, time shifts are applied in the spatial and wavenumber domains. These shifts are function of the local velocity model. In this paper, following the same strategy as the beamlet migration, we formulate the split-step Fourier method in the curvelet domain. Curvelets are fairly local in the spatial and wavenumber domains, justifying the use of local velocity values in the one-way strategy. In practice, the wavefield is decomposed into 2D curvelets at each extrapolation depth and for fixed frequencies. The derivation is validated through an application on 3D zero-offset migration in a heterogeneous model. This work should be understood as an important step towards a better understanding of the wave propagation in a multi-scale and multi-directional perspective.