Band-limited beam propagation and migration in TI media
Han Bingkai1,2, Gu Hanming1,2, Liu Shaoyong1,2
1. Institute of Geophysics and Geomatics, China University of Geoscience(Wuhan), Wuhan, Hubei 430074, China; 2. Hubei Subsurface Multi-scale Imaging Key Laboratory, Wuhan, Hubei 430074, China
Abstract:Seismic data are typical band-limited signals that limit the application of conventional high-frequency ray theory in seismic data processing and migration.In this paper, a band-limited beam propagation operator for TI media is developed, and it is applied to beam migration.Firstly, a band-limited ray tracing algorithm is developed under the local plane wave approximation, and this algorithm is extended to TI case.Then, the paraxial approximation is introduced to extrapolate the central band-limited ray to a band-limited beam propagator.Finally, the band-limited beam propagator is applied to TI beam migration.The operator can describe the characteristics of band-limited seismic wave propagation; meanwhile it inherit the advantages of ray based propagators, i.e., efficient and flexible.Numerical experiments show that the TI band-limited beams improve the illumination of complex salt structures and anisotropic areas, and enhance the quality of the imaging profile and generated angle domain common imaging gathers.
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