HR: 13:40h
AN: S33E-01 INVITED    [Abstracts]
TI: Multi-Frequency Diffraction Tomography and Imaging: Resolution and Fidelity Enhancement
AU: * Wu, R
EM: wrs@pmc.ucsc.edu
AF: University of California, Santa Cruz, 1156 High St., UCSC Earth Sciences, Santa Curz, CA 95060, United States
AB: Classic diffraction tomography is generalized to inhomogeneous background with finite data aperture (finite frequency band and finite spatial aperture of acquisition). Tomographic inversions can be summarized as a process of backpropagation plus filtering in the local angle domain. The backpropagation is a doubly focusing process, similar to the imaging principle in migration/imaging with modified imaging condition in the local angle domain. The filtering is a deconvolution in the local angle domain, which includes the correction factor for acquisition aperture and propagation effects in arbitrarily heterogeneous media. It is shown that multi-frequency diffraction tomography can enhance the resolution and the fidelity of the tomographic inversion, hence the image quality and inversion accuracy. The low frequency component can help in recovering the low wavenumber spectra of the structure (large-scale, smooth background), especially with the use of evanescent waves. Numerical examples of multi-frequency illumination and aperture effects, resolving kernel, spectral recovery and imaging enhancement will be shown to demonstrate the theory and method.
DE: 2487 Wave propagation (0689, 3285, 4275, 4455, 6934)
DE: 3205 Fourier analysis (3255)
DE: 3255 Spectral analysis (3205, 3280)
DE: 6982 Tomography and imaging (7270, 8180)
DE: 7260 Theory
SC: Seismology [S]
MN: 2007 Fall Meeting