Print Email Facebook Twitter Acoustic directional snapshot wavefield decomposition Title Acoustic directional snapshot wavefield decomposition Author Holicki, M.E. (TU Delft Applied Geophysics and Petrophysics) Drijkoningen, G.G. (TU Delft Applied Geophysics and Petrophysics) Wapenaar, C.P.A. (TU Delft Applied Geophysics and Petrophysics) Date 2018 Abstract Up–down wavefield decomposition is effectuated by a scaled addition or subtraction of the pressure and vertical particle velocity, generally on horizontal or vertical surfaces, and works well for data given on such surfaces. The method, however, is not applicable to decomposing a wavefield when it is given at one instance in time, i.e. on snapshots. Such situations occur when a wavefield is modelled with methods like finite-difference techniques, for the purpose of, for example, reverse time migration, where the entire wavefield is determined per time instance. We present an alternative decomposition method that is exact when working on snapshots of an acoustic wavefield in a homogeneous medium, but can easily be approximated to heterogeneous media, and allows the wavefield to be decomposed in arbitrary directions. Such a directional snapshot wavefield decomposition is achieved by recasting the acoustic system in terms of the time derivative of the pressure and the vertical particle velocity, as opposed to the vertical derivative in up–down decomposition for data given on a horizontal surface. As in up–down decomposition of data given at a horizontal surface, the system can be eigenvalue decomposed and the inverse of the eigenvector matrix decomposes the wavefield snapshot into fields of opposite directions, including up–down decomposition. As the vertical particle velocity can be rotated at will, this allows for decomposition of the wavefield into any spatial direction; even spatially varying directions are possible. We show the power and effectiveness of the method by synthetic examples and models of increasing complexity. Subject AcousticsModellingMulticomponentSeismics To reference this document use: http://resolver.tudelft.nl/uuid:ce065c7e-0042-4bb5-9a33-10950d2d0343 DOI https://doi.org/10.1111/1365-2478.12700 ISSN 0016-8025 Source Geophysical Prospecting, 67 (1), 32-51 Part of collection Institutional Repository Document type journal article Rights © 2018 M.E. Holicki, G.G. Drijkoningen, C.P.A. Wapenaar Files PDF Holicki_et_al_2018_Geophy ... ecting.pdf 8.02 MB Close viewer /islandora/object/uuid:ce065c7e-0042-4bb5-9a33-10950d2d0343/datastream/OBJ/view