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 | Elastic wave-mode separation for TTI media |  |
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I use a homogeneous TTI model to illustrate the separation of P-,
SV-, and SH-modes. The model has parameters
km/s,
km/s,
g/cm
,
,
,
,
, and
. Figure 14 shows a snapshot of the
elastic wavefields in the
,
, and
directions. A displacement
source located at the center of the model and oriented at tilt
45
and azimuth 45
is used to excite the
wavefield. Figure 15 shows successfully separated P-, SV-, and
SH-modes. In this model, the parameter
, which characterizes
the anisotropy of SH-mode, is set to zero so that the SH-mode
propagation is isotropic. For this homogeneous model, a spherical
wavefront in the SH-panel indicates successful separation of SV- and
SH-modes.
Because this model is homogeneous, the separation is implemented in
the wavenumber domain to reduce computation cost. For heterogeneous
models, 3D non-stationary filtering is necessary to separate different
wave-modes. I do not perform wave-mode separation in 3D heterogeneous
models because of the high computational cost, which will be discussed
in more detail in the following section.
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we3d-0,we3d-1,we3d-2
Figure 14. A snapshot of the elastic wavefield in the
,
and
directions for a 3D VTI model. The model has parameters
km/s,
km/s,
g/cm
,
,
, and
. A displacement source
oriented at 45
to the vertical direction and located at
coordinates
km and
km is used to simulate the elastic
anisotropic wavefield.
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P,SH,SV
Figure 15. Separated P-, SV- and SH-wave-modes for the elastic wavefields shown in
Figure 14.
P, SV, and SH are well separated from each other.
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 | Elastic wave-mode separation for TTI media |  |
![[pdf]](icons/pdf.png) |
Next: Discussion
Up: Examples
Previous: Marmousi II model
2013-08-29