def image_data(self,dat,dt,minf,maxf,vel,jf=1,nhx=0,nhy=0,sym=True,nrmax=3,eps=0.,dtmax=5e-05,wav=None,
ntx=0,nty=0,px=0,py=0,nthrds=1,sverb=True,wverb=False):
"""
3D migration of shot profile data via the one-way wave equation (single-square
root split-step fourier method).
Parameters:
dat - input shot profile data [ntr,nt]
dt - temporal sampling of input data
minf - minimum frequency to image in the data [Hz]
maxf - maximum frequency to image in the data [Hz]
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor [1]
nhx - number of subsurface offsets in x to compute [0]
nhy - number of subsurface offsets in y to compute [0]
sym - symmetrize the subsurface offsets [True]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
wav - input wavelet [None,assumes an impulse at zero lag]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for frequency parallelization [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
an image created from the data [nhy,nhx,nz,ny,nx]
"""
# Make sure data are same size as coordinates
if(dat.shape[0] != self.__ntr):
raise Exception("Data must have same number of traces passed to constructor")
# Get temporal axis
nt = dat.shape[-1]
# Create frequency domain source
if(wav is None):
wav = np.zeros(nt,dtype='float32')
wav[0] = 1.0
self.__nwo,self.__ow,self.__dw,wfft = fft1(wav,dt,minf=minf,maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[0] # Get the number of frequencies for imaging
self.__dwc = self.__dw*jf
if(sverb or wverb): print("Frequency axis: nw=%d ow=%f dw=%f"%(self.__nwc,self.__ow,self.__dwc))
# Create frequency domain data
_,_,_,dfft = fft1(dat,dt,minf=minf,maxf=maxf)
dfftd = dfft[:,::jf]
# Allocate the data for one shot
datw = np.zeros([self.__ny,self.__nx,self.__nwc],dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([self.__nwc,self.__ny,self.__nx],dtype='complex64')
# Single square root object
ssf = ssr3(self.__nx ,self.__ny,self.__nz , # Spatial Sizes
self.__dx ,self.__dy,self.__dz , # Spatial Samplings
self.__nwc,self.__ow,self.__dwc,eps, # Frequency axis
ntx,nty,px,py, # Taper and padding
dtmax,nrmax,nthrds) # Reference velocities and threads
# Compute slowness and reference slownesses
slo = 1/vel
ssf.set_slows(slo)
# Allocate partial image array
if(nhx == 0 and nhy == 0):
imgtmp = np.zeros([self.__nz,self.__ny,self.__nx],dtype='float32')
oimg = np.zeros([self.__nz,self.__ny,self.__nx],dtype='float32')
else:
if(sym):
# Create axes
self.__rnhx = 2*nhx+1; self.__ohx = -nhx*self.__dx; self.__dhx = self.__dx
self.__rnhy = 2*nhy+1; self.__ohy = -nhy*self.__dy; self.__dhy = self.__dy
imgtmp = np.zeros([self.__rnhy,self.__rnhx,self.__nz,self.__ny,self.__nx],dtype='float32')
oimg = np.zeros([self.__rnhy,self.__rnhx,self.__nz,self.__ny,self.__nx],dtype='float32')
else:
# Create axes
self.__rnhx = nhx+1; self.__ohx = 0; self.__dhx = self.__dx
self.__rnhy = nhy+1; self.__ohy = 0; self.__dhy = self.__dy
imgtmp = np.zeros([self.__rnhy,self.__rnhx,self.__nz,self.__ny,self.__nx],dtype='float32')
oimg = np.zeros([self.__rnhy,self.__rnhx,self.__nz,self.__ny,self.__nx],dtype='float32')
# Allocate memory necessary for extension
ssf.set_ext(nhy,nhx,sym)
# Loop over sources
ntr = 0
for iexp in progressbar(range(self.__nexp),"nexp:",verb=sverb):
# Get the source coordinates
sy = self.__srcys[iexp]; sx = self.__srcxs[iexp]
isy = int((sy-self.__oy)/self.__dy+0.5); isx = int((sx-self.__ox)/self.__dx+0.5)
# Create the source wavefield for this shot
sou[:] = 0.0
sou[:,isy,isx] = wfftd[:]
# Inject the data for this shot
datw[:] = 0.0
ssf.inject_data(self.__nrec[iexp],self.__recys[ntr:],self.__recxs[ntr:],self.__oy,self.__ox,dfftd[ntr:,:],datw)
datwt = np.ascontiguousarray(np.transpose(datw,(2,0,1))) # [ny,nx,nwc] -> [nwc,ny,nx]
# Initialize temporary image
imgtmp[:] = 0.0
if(nhx == 0 and nhy == 0):
# Conventional imaging
ssf.migallw(datwt,sou,imgtmp,wverb)
else:
# Extended imaging
ssf.migoffallw(datwt,sou,imgtmp,wverb)
oimg += imgtmp
# Increase number of traces
ntr += self.__nrec[iexp]
# Free memory for extension
if(nhx != 0 or nhy != 0):
ssf.del_ext()
return oimg
def awemva(self,dimg,dat,dt,minf,maxf,vel,jf=1,nrmax=3,eps=0.,dtmax=5e-05,wav=None,
ntx=0,nty=0,px=0,py=0,nthrds=1,sverb=True,wverb=False):
"""
3D Adjoint WEMVA operator
Parameters:
dat - input shot profile data [ntr,nt]
dt - temporal sampling of input data
minf - minimum frequency to image in the data [Hz]
maxf - maximum frequency to image in the data [Hz]
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor [1]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
wav - input wavelet [None,assumes an impulse at zero lag]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for frequency parallelization [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
a slowness perturbation (adjoint wemva applied to image perturbation) [nz,ny,nx]
"""
# Make sure data are same size as coordinates
if(dat.shape[0] != self.__ntr):
raise Exception("Data must have same number of traces passed to constructor")
# Get temporal axis
nt = dat.shape[-1]
# Create frequency domain source
if(wav is None):
wav = np.zeros(nt,dtype='float32')
wav[0] = 1.0
self.__nwo,self.__ow,self.__dw,wfft = fft1(wav,dt,minf=minf,maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[0] # Get the number of frequencies for imaging
self.__dwc = self.__dw*jf
if(sverb or wverb): print("Frequency axis: nw=%d ow=%f dw=%f"%(self.__nwc,self.__ow,self.__dwc))
# Create frequency domain data
_,_,_,dfft = fft1(dat,dt,minf=minf,maxf=maxf)
dfftd = dfft[:,::jf]
# Allocate the data for one shot
datw = np.zeros([self.__ny,self.__nx,self.__nwc],dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([self.__nwc,self.__ny,self.__nx],dtype='complex64')
# Single square root object
ssf = ssr3(self.__nx ,self.__ny,self.__nz , # Spatial Sizes
self.__dx ,self.__dy,self.__dz , # Spatial Samplings
self.__nwc,self.__ow,self.__dwc,eps, # Frequency axis
ntx,nty,px,py, # Taper and padding
dtmax,nrmax,nthrds) # Reference velocities and threads
# Compute slowness and reference slownesses
slo = 1/vel
ssf.set_slows(slo)
# Allocate temporary partial image
dslotmp = np.zeros([self.__nz,self.__ny,self.__nx],dtype='complex64')
odslo = np.zeros([self.__nz,self.__ny,self.__nx],dtype='complex64')
# Loop over sources
ntr = 0
for iexp in progressbar(range(self.__nexp),"nexp:",verb=sverb):
# Get the source coordinates
sy = self.__srcys[iexp]; sx = self.__srcxs[iexp]
isy = int((sy-self.__oy)/self.__dy+0.5); isx = int((sx-self.__ox)/self.__dx+0.5)
# Create the source wavefield for this shot
sou[:] = 0.0
sou[:,isy,isx] = wfftd[:]
# Inject the data for this shot
datw[:] = 0.0
ssf.inject_data(self.__nrec[iexp],self.__recys[ntr:],self.__recxs[ntr:],self.__oy,self.__ox,dfftd[ntr:,:],datw)
datwt = np.ascontiguousarray(np.transpose(datw,(2,0,1))) # [ny,nx,nwc] -> [nwc,ny,nx]
# Initialize temporary image
dslotmp[:] = 0.0
# Adjoint WEMVA
ssf.awemvaallw(sou,datwt,dslotmp,dimg,verb=wverb)
odslo += dslotmp
# Increase number of traces
ntr += self.__nrec[iexp]
return np.real(odslo)
def awemva(self,
dimg,
dat,
dt,
minf,
maxf,
vel,
jf=1,
nrmax=3,
eps=0.0,
dtmax=5e-05,
wav=None,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
sverb=True,
wverb=False) -> np.ndarray:
"""
Applies the forward WEMVA operator
Parameters:
dimg - the input image perturbation
dat - the input data
dt - temporal sampling interval
minf - minimum frequency to image in the data [Hz]
maxf - maximim frequency to image in the data [Hz]
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor [1]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
wav - input wavelet [None,assumes an impulse at zero lag]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for parallelizing over frequency [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
a slowness perturbation (adjoint wemva applied to image) [nz,ny,nx]
"""
# Get temporal axis
nt = dat.shape[-1]
# Create frequency domain source
if (wav is None):
wav = np.zeros(nt, dtype='float32')
wav[0] = 1.0
self.__nwo, self.__ow, self.__dw, wfft = self.fft1(wav,
dt,
minf=minf,
maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[
0] # Get the number of frequencies for imaging
self.__dwc = self.__dw * jf
if (sverb or wverb):
print("Frequency axis: nw=%d ow=%f dw=%f" %
(self.__nwc, self.__ow, self.__dwc))
# Create frequency domain data
_, _, _, dfft = self.fft1(dat, dt, minf=minf, maxf=maxf)
dfftd = dfft[:, ::jf]
datt = np.transpose(
dfftd,
(0, 1, 4, 2, 3)) # [nsy,nsx,ny,nx,nwc] -> [nsy,nsx,nwc,ny,nx]
datw = np.ascontiguousarray(
datt.reshape([self.__nexp, self.__nwc, self.__ny, self.__nx]))
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
self.__nwc,
self.__ow,
self.__dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities
# Compute slowness and reference slownesses
slo = 1 / vel
ssf.set_slows(slo)
dsloar = np.zeros([self.__nexp, self.__nz, self.__ny, self.__nx],
dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([self.__nwc, self.__ny, self.__nx], dtype='complex64')
# Loop over sources
k = 0
for icrd in progressbar(self.__scoords, "nexp:", verb=sverb):
# Get the source coordinates
sy = icrd[0]
sx = icrd[1]
# Create the source for this shot
sou[:] = 0.0
sou[:, sy, sx] = wfftd[:]
ssf.awemvaallw(sou, datw[k], dsloar[k], dimg, verb=wverb)
k += 1
# Sum over all partial images
dslo = np.sum(dsloar, axis=0)
return np.real(dslo)
def model_data(self,wav,dt,t0,minf,maxf,vel,ref,jf=1,nrmax=3,eps=0.,dtmax=5e-05,time=True,
ntx=0,nty=0,px=0,py=0,nthrds=1,sverb=True,wverb=False):
"""
3D modeling of single scattered (Born) data with the one-way
wave equation (single square root (SSR), split-step Fourier method).
Parameters:
wav - the input wavelet (source time function) [nt]
dt - sampling interval of wavelet
t0 - time-zero of wavelet (e.g., peak of ricker wavelet)
minf - minimum frequency to propagate [Hz]
maxf - maximum frequency to propagate [Hz]
vel - input velocity model [nz,ny,nx]
ref - input reflectivity model [nz,ny,nx]
jf - frequency decimation factor
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
time - return the data back in the time domain [True]
ntx - size of taper in x direction (samples) [0]
nty - size of taper in y direction (samples) [0]
px - amount of padding in x direction (samples)
py - amount of padding in y direction (samples)
nthrds - number of OpenMP threads to use for frequency parallelization [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
the data at the surface (in time or frequency) [nw,nry,nrx]
"""
# Save wavelet temporal parameters
nt = wav.shape[0]; it0 = int(t0/dt)
# Create the input frequency domain source and get original frequency axis
self.__nwo,self.__ow,self.__dw,wfft = fft1(wav,dt,minf=minf,maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[0] # Get the number of frequencies to compute
self.__dwc = jf*self.__dw
if(sverb or wverb): print("Frequency axis: nw=%d ow=%f dw=%f"%(self.__nwc,self.__ow,self.__dwc))
# Single square root object
ssf = ssr3(self.__nx ,self.__ny,self.__nz , # Spatial Sizes
self.__dx ,self.__dy,self.__dz , # Spatial Samplings
self.__nwc,self.__ow,self.__dwc,eps, # Frequency axis
ntx,nty,px,py, # Taper and padding
dtmax,nrmax,nthrds) # Reference velocities and threads
# Compute slowness and reference slownesses
slo = 1/vel
ssf.set_slows(slo)
# Allocate output data (surface wavefield) and receiver data
datw = np.zeros([self.__nwc,self.__ny,self.__nx],dtype='complex64')
recw = np.zeros([self.__ntr,self.__nwc],dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([self.__nwc,self.__ny,self.__nx],dtype='complex64')
# Loop over sources
ntr = 0
for iexp in progressbar(range(self.__nexp),"nexp:",verb=sverb):
# Get the source coordinates
sy = self.__srcys[iexp]; sx = self.__srcxs[iexp]
isy = int((sy-self.__oy)/self.__dy+0.5); isx = int((sx-self.__ox)/self.__dx+0.5)
# Create the source for this shot
sou[:] = 0.0
sou[:,isy,isx] = wfftd[:]
# Downward continuation
datw[:] = 0.0
ssf.modallw(ref,sou,datw,wverb)
# Restrict to receiver locations
datwt = np.ascontiguousarray(np.transpose(datw,(1,2,0))) # [nwc,ny,nx] -> [ny,nx,nwc]
ssf.restrict_data(self.__nrec[iexp],self.__recys[ntr:],self.__recxs[ntr:],self.__oy,self.__ox,datwt,recw[ntr:,:])
# Increase number of traces
ntr += self.__nrec[iexp]
if(time):
rect = ifft1(recw,self.__nwo,self.__ow,self.__dw,nt,it0)
return rect
else:
return recw
def image_data(self,
dat,
dt,
minf,
maxf,
vel,
jf=1,
nhx=0,
nhy=0,
sym=True,
nrmax=3,
eps=0.0,
dtmax=5e-05,
wav=None,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
sverb=True,
wverb=False) -> np.ndarray:
"""
3D migration of shot profile data via the one-way wave equation (single-square
root split-step fourier method). Input data are assumed to follow
the default geometry (sources and receivers on a regular grid)
Parameters:
dat - input shot profile data [nsy,nsx,nry,nrx,nt]
dt - temporal sampling of input data
minf - minimum frequency to image in the data [Hz]
maxf - maximum frequency to image in the data [Hz]
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor
nhx - number of subsurface offsets in x to compute [0]
nhy - number of subsurface offsets in y to compute [0]
sym - symmetrize the subsurface offsets [True]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
wav - input wavelet [None,assumes an impulse at zero lag]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for parallelizing over frequency [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
an image created from the data [nhy,nhx,nz,ny,nx]
"""
# Get temporal axis
nt = dat.shape[-1]
# Create frequency domain source
if (wav is None):
wav = np.zeros(nt, dtype='float32')
wav[0] = 1.0
self.__nwo, self.__ow, self.__dw, wfft = self.fft1(wav,
dt,
minf=minf,
maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[
0] # Get the number of frequencies for imaging
self.__dwc = self.__dw * jf
if (sverb or wverb):
print("Frequency axis: nw=%d ow=%f dw=%f" %
(self.__nwc, self.__ow, self.__dwc))
# Create frequency domain data
_, _, _, dfft = self.fft1(dat, dt, minf=minf, maxf=maxf)
dfftd = dfft[:, ::jf]
datt = np.transpose(
dfftd,
(0, 1, 4, 2, 3)) # [nsy,nsx,ny,nx,nwc] -> [nsy,nsx,nwc,ny,nx]
datw = np.ascontiguousarray(
datt.reshape([self.__nexp, self.__nwc, self.__ny, self.__nx]))
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
self.__nwc,
self.__ow,
self.__dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities
# Compute slowness and reference slownesses
slo = 1 / vel
ssf.set_slows(slo)
# Allocate partial image array
if (nhx == 0 and nhy == 0):
imgar = np.zeros([self.__nexp, self.__nz, self.__ny, self.__nx],
dtype='float32')
else:
if (sym):
# Create axes
self.__rnhx = 2 * nhx + 1
self.__ohx = -nhx * self.__dx
self.__dhx = self.__dx
self.__rnhy = 2 * nhy + 1
self.__ohy = -nhy * self.__dy
self.__dhy = self.__dy
# Allocate image array
imgar = np.zeros([
self.__nexp, self.__rnhy, self.__rnhx, self.__nz,
self.__ny, self.__nx
],
dtype='float32')
else:
# Create axes
self.__rnhx = nhx + 1
self.__ohx = 0
self.__dhx = self.__dx
self.__rnhy = nhy + 1
self.__ohy = 0
self.__dhy = self.__dy
# Allocate image array
imgar = np.zeros([
self.__nexp, self.__rnhy, self.__rnhx, self.__nz,
self.__ny, self.__nx
],
dtype='float32')
# Allocate memory necessary for extension
ssf.set_ext(nhy, nhx, sym)
# Allocate the source for one shot
sou = np.zeros([self.__nwc, self.__ny, self.__nx], dtype='complex64')
# Loop over sources
k = 0
for icrd in progressbar(self.__scoords, "nexp:", verb=sverb):
# Get the source coordinates
sy = icrd[0]
sx = icrd[1]
# Create the source for this shot
sou[:] = 0.0
sou[:, sy, sx] = wfftd[:]
if (nhx == 0 and nhy == 0):
# Conventional imaging
ssf.migallw(datw[k], sou, imgar[k], wverb)
else:
# Extended imaging
ssf.migoffallw(datw[k], sou, imgar[k], wverb)
k += 1
# Sum over all partial images
img = np.sum(imgar, axis=0)
# Free memory for extension
if (nhx != 0 or nhy != 0):
ssf.del_ext()
return img
def model_data(self,
wav,
dt,
t0,
minf,
maxf,
vel,
ref,
jf=1,
nrmax=3,
eps=0.,
dtmax=5e-05,
time=True,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
sverb=True,
wverb=False) -> np.ndarray:
"""
3D modeling of single scattered (Born) data with the one-way
wave equation (single square root (SSR), split-step Fourier method).
Parameters:
wav - the input wavelet (source time function) [nt]
dt - sampling interval of wavelet
t0 - time-zero of wavelet (e.g., peak of ricker wavelet)
minf - minimum frequency to propagate [Hz]
maxf - maximum frequency to propagate [Hz]
vel - input velocity model [nz,ny,nx]
ref - input reflectivity model [nz,ny,nx]
jf - frequency decimation factor [1]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
time - return the data back in the time domain [True]
ntx - size of taper in x direction (samples) [0]
nty - size of taper in y direction (samples) [0]
px - amount of padding in x direction (samples)
py - amount of padding in y direction (samples)
nthrds - number of OpenMP threads for parallelizing over frequency [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progressbar [False]
Returns the data at the surface (in time or frequency) [nw,nry,nrx]
"""
# Save wavelet temporal parameters
nt = wav.shape[0]
it0 = int(t0 / dt)
# Create the input frequency domain source and get original frequency axis
self.__nwo, self.__ow, self.__dw, wfft = self.fft1(wav,
dt,
minf=minf,
maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[0] # Get the number of frequencies to compute
self.__dwc = jf * self.__dw
if (sverb or wverb):
print("Frequency axis: nw=%d ow=%f dw=%f" %
(self.__nwc, self.__ow, self.__dwc))
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
self.__nwc,
self.__ow,
self.__dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities
# Compute slowness and reference slownesses
slo = 1 / vel
ssf.set_slows(slo)
# Allocate output data (surface wavefield)
datw = np.zeros([self.__nexp, self.__nwc, self.__ny, self.__nx],
dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([self.__nwc, self.__ny, self.__nx], dtype='complex64')
# Loop over sources
k = 0
for icrd in progressbar(self.__scoords, "nexp:", verb=sverb):
# Get the source coordinates
sy = icrd[0]
sx = icrd[1]
# Create the source for this shot
sou[:] = 0.0
sou[:, sy, sx] = wfftd[:]
# Downward continuation
ssf.modallw(ref, sou, datw[k], wverb)
k += 1
# Reshape output data
datwr = datw.reshape(
[self.__nsy, self.__nsx, self.__nwc, self.__ny, self.__nx])
if (time):
# Inverse fourier transform
datt = self.data_f2t(datwr, self.__nwo, self.__ow, self.__dwc, nt,
it0)
return datt
else:
return datwr
def image_data(self,
rec,
owc,
dwc,
vel,
nhx=0,
nhy=0,
sym=True,
eps=0,
nrmax=3,
dtmax=5e-05,
wav=None,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
sverb=True,
wverb=False):
"""
3D migration of shot profile data via the one-way wave equation (single-square
root split-step fourier method). Input data are assumed to follow
the default geometry (sources and receivers on a regular grid)
Parameters:
rec - flattened input shot profile data
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor
nhx - number of subsurface offsets in x to compute [0]
nhy - number of subsurface offsets in y to compute [0]
sym - symmetrize the subsurface offsets [True]
nrmax - maximum number of reference velocities [3]
dtmax - maximum time error [5e-05]
wav - input wavelet [None,assumes an impulse at zero lag]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for parallelizing over frequency [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
nchnks - number of chunks to distribute over cluster
client - dask client for distributing work over a cluster
Returns:
an image created from the data [nhy,nhx,nz,ny,nx]
"""
# Make sure data are same size as coordinates
if (rec.shape[0] != self.__ntr):
raise Exception(
"Data must have same number of traces passed to constructor")
nwc = wav.shape[0]
if (rec.shape[-1] != nwc):
raise Exception("Data and wavelet must have same frequency axis")
# Allocate source and data for one shot
datw = np.zeros([self.__ny, self.__nx, nwc], dtype='complex64')
sou = np.zeros([nwc, self.__ny, self.__nx], dtype='complex64')
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
nwc,
owc,
dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities and threads
# Compute slowness and reference slownesses
slo = 1 / vel
ssf.set_slows(slo)
# Allocate partial image array
if (nhx == 0 and nhy == 0):
imgtmp = np.zeros([self.__nz, self.__ny, self.__nx],
dtype='float32')
oimg = np.zeros([self.__nz, self.__ny, self.__nx], dtype='float32')
else:
if (sym):
# Create axes
self.__rnhx = 2 * nhx + 1
self.__ohx = -nhx * self.__dx
self.__dhx = self.__dx
self.__rnhy = 2 * nhy + 1
self.__ohy = -nhy * self.__dy
self.__dhy = self.__dy
imgtmp = np.zeros([
self.__rnhy, self.__rnhx, self.__nz, self.__ny, self.__nx
],
dtype='float32')
oimg = np.zeros([
self.__rnhy, self.__rnhx, self.__nz, self.__ny, self.__nx
],
dtype='float32')
else:
# Create axes
self.__rnhx = nhx + 1
self.__ohx = 0
self.__dhx = self.__dx
self.__rnhy = nhy + 1
self.__ohy = 0
self.__dhy = self.__dy
imgtmp = np.zeros([
self.__rnhy, self.__rnhx, self.__nz, self.__ny, self.__nx
],
dtype='float32')
oimg = np.zeros([
self.__rnhy, self.__rnhx, self.__nz, self.__ny, self.__nx
],
dtype='float32')
# Allocate memory necessary for extension
ssf.set_ext(nhy, nhx, sym, True)
#ssf.set_ext(nhy,nhx,sym,False)
# Loop over sources
ntr = 0
for iexp in progressbar(range(self.__nexp), "nexp:", verb=sverb):
# Get the source coordinates
sy = self.__srcy[iexp]
sx = self.__srcx[iexp]
isy = int((sy - self.__oy) / self.__dy + 0.5)
isx = int((sx - self.__ox) / self.__dx + 0.5)
# Create the source wavefield for this shot
sou[:] = 0.0
sou[:, isy, isx] = wav[:]
# Inject the data for this shot
datw[:] = 0.0
ssf.inject_data(self.__nrec[iexp], self.__recy[ntr:],
self.__recx[ntr:], self.__oy, self.__ox,
rec[ntr:, :], datw)
datwt = np.ascontiguousarray(np.transpose(
datw, (2, 0, 1))) # [ny,nx,nwc] -> [nwc,ny,nx]
# Initialize temporary image
imgtmp[:] = 0.0
if (nhx == 0 and nhy == 0):
# Conventional imaging
ssf.migallw(datwt, sou, imgtmp, wverb)
else:
# Extended imaging
ssf.migoffallw(datwt, sou, imgtmp, wverb)
#ssf.migoffallwbig(datwt,sou,imgtmp,wverb)
oimg += imgtmp
# Increase number of traces
ntr += self.__nrec[iexp]
# Free memory for extension
if (nhx != 0 or nhy != 0):
ssf.del_ext()
return oimg
def model_data(self,
wav,
t0,
owc,
dwc,
vel,
ref,
nrmax=3,
eps=0.,
dtmax=5e-05,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
sverb=True,
wverb=True):
"""
3D modeling of single scattered (Born) data with the one-way
wave equation (single square root (SSR), split-step Fourier method).
Parameters:
wav - the input wavelet (source time function) [nt]
t0 - time zero of input wavelet
owc - minimum frequency of wavelet
dwc - frequency sampling of wavelet
vel - input velocity model [nz,ny,nx]
ref - input reflectivity model [nz,ny,nx]
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
ntx - size of taper in x direction (samples) [0]
nty - size of taper in y direction (samples) [0]
px - amount of padding in x direction (samples)
py - amount of padding in y direction (samples)
nthrds - number of OpenMP threads to use for frequency parallelization [1]
sverb - verbosity flag for shot progress bar [True]
wverb - verbosity flag for frequency progress bar [False]
Returns:
the data at the surface [nw,nry,nrx]
"""
# Get dimensions
nwc = wav.shape[0]
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
nwc,
owc,
dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities and threads
# Compute slowness and reference slownesses
slo = 1 / vel
ssf.set_slows(slo)
# Allocate output data (surface wavefield) and receiver data
datw = np.zeros([nwc, self.__ny, self.__nx], dtype='complex64')
recw = np.zeros([self.__ntr, nwc], dtype='complex64')
# Allocate the source for one shot
sou = np.zeros([nwc, self.__ny, self.__nx], dtype='complex64')
# Loop over sources
ntr = 0
for iexp in progressbar(range(self.__nexp), "nexp:", verb=sverb):
# Get the source coordinates
sy = self.__srcy[iexp]
sx = self.__srcx[iexp]
isy = int((sy - self.__oy) / self.__dy + 0.5)
isx = int((sx - self.__ox) / self.__dx + 0.5)
# Create the source for this shot
sou[:] = 0.0
sou[:, isy, isx] = wav[:]
# Downward continuation
datw[:] = 0.0
ssf.modallw(ref, sou, datw, wverb)
# Restrict to receiver locations
datwt = np.ascontiguousarray(np.transpose(
datw, (1, 2, 0))) # [nwc,ny,nx] -> [ny,nx,nwc]
ssf.restrict_data(self.__nrec[iexp], self.__recy[ntr:],
self.__recx[ntr:], self.__oy, self.__ox, datwt,
recw[ntr:, :])
# Increase number of traces
ntr += self.__nrec[iexp]
# Apply phase shift to data to account for t0
recs = phzshft(recw, owc, dwc, t0)
return recs
def image_data(self,
dat,
dt,
minf,
maxf,
vel,
jf=1,
nrmax=3,
eps=0.,
dtmax=5e-05,
ntx=0,
nty=0,
px=0,
py=0,
nthrds=1,
wverb=True):
"""
3D migration of zero-offset data via the one-way wave equation (single-square
root split-step fourier method)
Parameters:
dat - input shot profile data [ny,nx,nt]
dt - temporal sampling of input data
minf - minimum frequency to image in the data [Hz]
maxf - maximum frequency to image in the data [Hz]
vel - input migration velocity model [nz,ny,nx]
jf - frequency decimation factor
nrmax - maximum number of reference velocities [3]
eps - stability parameter [0.]
dtmax - maximum time error [5e-05]
ntx - size of taper in x direction [0]
nty - size of taper in y direction [0]
px - amount of padding in x direction (samples) [0]
py - amount of padding in y direction (samples) [0]
nthrds - number of OpenMP threads for parallelizing over frequency [1]
wverb - verbosity flag for frequency progress bar [True]
Returns:
an image created from the data [nz,ny,nx]
"""
# Get temporal axis
nt = dat.shape[-1]
# Create frequency domain source
wav = np.zeros(nt, dtype='float32')
wav[0] = 1.0
self.__nwo, self.__ow, self.__dw, wfft = self.fft1(wav,
dt,
minf=minf,
maxf=maxf)
wfftd = wfft[::jf]
self.__nwc = wfftd.shape[
0] # Get the number of frequencies for imaging
self.__dwc = self.__dw * jf
if (wverb):
print("Frequency axis: nw=%d ow=%f dw=%f" %
(self.__nwc, self.__ow, self.__dwc))
# Create frequency domain data
_, _, _, dfft = self.fft1(dat, dt, minf=minf, maxf=maxf)
dfftd = dfft[:, ::jf]
datt = np.transpose(dfftd, (2, 0, 1)) # [ny,nx,nwc] -> [nwc,ny,nx]
datw = np.ascontiguousarray(
datt.reshape([self.__nwc, self.__ny, self.__nx]))
# Single square root object
ssf = ssr3(
self.__nx,
self.__ny,
self.__nz, # Spatial Sizes
self.__dx,
self.__dy,
self.__dz, # Spatial Samplings
self.__nwc,
self.__ow,
self.__dwc,
eps, # Frequency axis
ntx,
nty,
px,
py, # Taper and padding
dtmax,
nrmax,
nthrds) # Reference velocities
# Output image
img = np.zeros([self.__nz, self.__ny, self.__nx], dtype='float32')
# Compute slowness and reference slownesses
slo = 2 / vel # Two-way travel time
ssf.set_slows(slo)
# Image for all frequencies
ssf.migallwzo(datw, img, wverb)
return img
