HR: 1340h
AN: S33A-1089    [Abstracts]
TI: Beamlet imaging using local cosine basis and aperture correction for true-reflection imaging
AU: * Luo, M
EM: mqluo@es.ucsc.edu
AF: Earth Sciences, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 United States
AU: Wu, R
EM: wrs@es.ucsc.edu
AF: Earth Sciences, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 United States
AB: Beamlet imaging using local cosine basis (LCB) is implemented and acquisition aperture corrections are introduced in the local angle-domain (beamlet domain). In beamlet migration, both the source field and the receiver array field are decomposed into LCB beamlets and sunk down to image levels using beamlet propagators. Imaging condition can be applied either in beamlet domain or space domain. The beamlet propagators have localization in both the spatial location and the direction. In addition, beamlet propagators have wide-angle capacity, high-resolution, high-fidelity to amplitude information, and no numerical dispersion and numerical anisotropy, Using the beamlet decomposition (local angle-domain) of Green­_s function, acquisition aperture corrections for image amplitudes in local angle-domain are formulated and applied to the local image matrix, which is obtained from the imaging condition in local angle-domain (beamlet domain). The resulted images are true-reflection images, whose amplitudes are proportional to the total scattering coefficients of local heterogeneities. The local image matrices can be reduced to common refection-angle image (CRAI) gathers and common dip-angle image (CDAI) gathers. CRAI gathers can be used for local AVA analysis. Numerical examples for a four layers model with curved interfaces and for the SEG-EAGE salt model are shown to validate the approach.
DE: 7260 Theory and modeling
DE: 7294 Instruments and techniques
DE: 7203 Body wave propagation
DE: 7218 Lithosphere and upper mantle
DE: 3260 Inverse theory
SC: Seismology [S]
MN: 2004 AGU Fall Meeting