Wavefield extrapolation in laterally-varying tilted TI media
نویسنده
چکیده
A new wavefield extrapolation method has been developed that allows the propagation of waves in an anisotropic medium. The anisotropic medium considered here is transversely isotropic (TI) with an axis of symmetry. Our method applies an asymmetric explicit correction filter after the normal isotropic extrapolation operator. It is stable and suitable for laterally varying TI media. This new scheme is useful to extrapolate wavefields in a vertical transversely isotropic (VTI) medium in tilted coordinates. The explicit correction operator, designed by a weighted least-square method, is stable and accurate for the desired wavenumbers. Impulse responses from this scheme and the anisotropic phase-shift method are compared to illustrate the algorithm.
منابع مشابه
3D wavefield extrapolation in laterally-varying tilted TI media
We develop a new 3D wavefield-extrapolation method for a transversely isotropic (TI) medium with a symmetry axis. The wavefield extrapolation is done by an implicit isotropic extrapolation operator with an explicit correction operator. The explicit correction is a 2D convolution operator in the space domain, whose coefficients are estimated by a weighted least-squares method in the Fourier doma...
متن کاملImaging steeply dipping reflectors in TI media by wavefield extrapolation
We develop an anisotropic plane-wave migration method based on wavefield extrapolation. In this new scheme, we decompose both source and receiver wavefields into plane waves by delaying shots. For each plane wave, we design a tilted coordinate system whose tilting angle depends on the propagation direction of the plane wave. The wavefield extrapolation is done by an implicit isotropic operator ...
متن کاملWavefield extrapolation by nonstationary phase shift
The phase shift method of wavefield extrapolation applies a phase shift in the Fourier domain to deduce a scalar wavefield at one depth level given its value at another. The phase shift operator varies with frequency and wavenumber and assumes constant velocity across the extrapolation step. We use nonstationary filter theory to generalize this method to nonstationary phase shift (NSPS) which a...
متن کاملApplications of Inverse Methods to the Analysis of Refraction and Wide-angle Seismic Data
The refraction inverse problem was initially investigated by Herglotz (1907), Bateman (1910), and Wiechert and Geiger (1910) who applied Abel transforms for the inversion of seismic travel-times in radially varying media. For smoothly varying media in the absence of low velocity zones, this formulation provides an inverse solution which includes ray bending. In the presence of low velocity zone...
متن کاملExploring three-dimensional implicit wavefield extrapolation with the helix transform
Implicit extrapolation is an efficient and unconditionally stable method of wavefield continuation. Unfortunately, implicit wave extrapolation in three dimensions requires an expensive solution of a large system of linear equations. However, by mapping the computational domain into one dimension via the helix transform, we show that the matrix inversion problem can be recast in terms of an effi...
متن کامل