pylops.waveeqprocessing.UpDownComposition3D¶

pylops.waveeqprocessing.
UpDownComposition3D
(nt, nr, dt, dr, rho, vel, nffts=(None, None, None), critical=100.0, ntaper=10, scaling=1.0, backend='numpy', dtype='complex128')[source]¶ 3D Updown wavefield composition.
Apply multicomponent seismic wavefield composition from its up and downgoing constituents. The input model required by the operator should be created by flattening the separated wavefields of size \(\lbrack n_{r_y} \times n_{r_x} \times n_t \rbrack\) concatenated along the first spatial axis.
Similarly, the data is also a flattened concatenation of pressure and vertical particle velocity wavefields.
Parameters:  nt :
int
Number of samples along the time axis
 nr :
tuple
Number of samples along the receiver axes
 dt :
float
Sampling along the time axis
 dr :
tuple
Samplings along the receiver array
 rho :
float
Density \(\rho\) along the receiver array (must be constant)
 vel :
float
Velocity \(c\) along the receiver array (must be constant)
 nffts :
tuple
, optional Number of samples along the wavenumbers and frequency axes (for the wavenumbers axes the same order as
nr
anddr
must be followed) critical :
float
, optional Percentage of angles to retain in obliquity factor. For example, if
critical=100
only angles below the critical angle \(\sqrt{k_y^2 + k_x^2} < \frac{\omega}{c}\) will be retained ntaper :
float
, optional Number of samples of taper applied to obliquity factor around critical angle
 scaling :
float
, optional Scaling to apply to the operator (see Notes for more details)
 backend :
str
, optional Backend used for creation of obliquity factor operator (
numpy
orcupy
) dtype :
str
, optional Type of elements in input array.
Returns:  UDop :
pylops.LinearOperator
Updown wavefield composition operator
See also
UpDownComposition2D
 2D Wavefield composition
WavefieldDecomposition
 Wavefield decomposition
Notes
Multicomponent seismic data \(p(y, x, t)\) and \(v_z(y, x, t)\) can be synthesized in the frequencywavenumber domain as the superposition of the up and downgoing constituents of the pressure wavefield (\(p^(y, x, t)\) and \(p^+(y, x, t)\)) as described
pylops.waveeqprocessing.UpDownComposition2D
.Here the vertical wavenumber \(k_z\) is defined as \(k_z=\sqrt{\frac{\omega^2}{c^2}  k_y^2  k_x^2}\).
 nt :