pylops.waveeqprocessing.UpDownComposition3D#
- pylops.waveeqprocessing.UpDownComposition3D(nt, nr, dt, dr, rho, vel, nffts=(None, None, None), critical=100.0, ntaper=10, scaling=1.0, fftengine='scipy', backend='numpy', dtype='complex128', name='U')[source]#
3D Up-down wavefield composition.
Apply multi-component seismic wavefield composition from its up- and down-going 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)
- fftengine
str
, optional New in version 2.3.0.
Engine used for fft computation (
numpy
orscipy
). Choosenumpy
when working with cupy and jax arrays.- backend
str
, optional Backend used for creation of obliquity factor operator (
numpy
orcupy
)- dtype
str
, optional Type of elements in input array.
- name
str
, optional New in version 2.0.0.
Name of operator (to be used by
pylops.utils.describe.describe
)
- nt
- Returns
- UDop
pylops.LinearOperator
Up-down wavefield composition operator
- UDop
See also
UpDownComposition2D
2D Wavefield composition
WavefieldDecomposition
Wavefield decomposition
Notes
Multi-component seismic data \(p(y, x, t)\) and \(v_z(y, x, t)\) can be synthesized in the frequency-wavenumber 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 \(k_z=\sqrt{\frac{\omega^2}{c^2} - k_y^2 - k_x^2}\).