Extended local Born Fourier migration method

Citation
Lj. Huang et al., Extended local Born Fourier migration method, GEOPHYSICS, 64(5), 1999, pp. 1524-1534
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
GEOPHYSICS
ISSN journal
0016-8033 → ACNP
Volume
64
Issue
5
Year of publication
1999
Pages
1524 - 1534
Database
ISI
SICI code
0016-8033(199909/10)64:5<1524:ELBFMM>2.0.ZU;2-D
Abstract
A migration approach based on a local application of the Born approximation within each extrapolation interval contains a singularity that can make di rect application unstable. Previous authors have suggested adding an imagin ary part to the vertical wavenumber to eliminate the singularity. However, their method requires that the reference slowness must be the maximum slown ess of a given layer; consequently, the slowness perturbations are larger t han those when the average slowness is selected as a reference slowness. Th erefore, its applicability is limited. We develop an extended local Born Fo urier migration method that circumvents the singularity problem of the loca l Born solution and makes it possible to choose the average slowness as a r eference slowness. It is computationally efficient because of the use of a fast Fourier transform algorithm. It can handle wider angles (or steeper in terfaces) and scattering effects of heterogeneities more accurately than th e split-step Fourier (SSF) method, which accounts for only the phase change as a result of the slowness perturbations but not amplitude change. To han dle large lateral slowness variations, we introduce different reference slo wnesses in different regions of a medium to ensure the condition of small p erturbation. The migration result obtained using the extended local Born Fo urier method with multiple reference slownesses demonstrates that the metho d can produce high-quality images of complex structures with large lateral slowness variations.