Anisotropic velocity models
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The dimensions of the velocity models and measurement
configurations are derived from the 2-D Marmousi model and dataset
(Versteeg & Grau, 1991). The horizontal dimensions of the velocity
model are 9.2 km x 10 km and the depth is 3 km.
The velocity model
is composed of two layers separated by one non-inclined curved
interface.
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The recorded wave field
is computed in velocity models
composed of two layers with
the triclinic anisotropy representing dry Vosges sandstone
(Mensch & Rasolofosaon, 1997) and
velocity gradients in the upper layer.
The bottom layer is isotropic and homogeneous.
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The migration is performed
using
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correct single-layer
heterogeneous velocity models
with triclinic anisotropy and vertical velocity
gradients and
-
incorrect single-layer
homogeneous velocity models
with the triclinic anisotropy, VTI symmetry and HTI symmetry
used by Bucha (2011, 2012a, 2012b). Constant elastic moduli for homogeneous
models are calculated as the average of the correct heterogeneous
velocity models.