SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUINVCO3D - Seismic INVersion of Common Offset data with V(X,Y,Z) velocity
function in 3D
suinvco3d <infile >outfile [optional parameters]
Required Parameters:
vfile= file containing velocity array v[nvy][nvx][nvz]
nzv= number of z samples (1st dimension) in velocity
nxm= number of midpoints of input traces
nym= number of lines
geo_type= geometry type
1 ---- general velocity distribution v(x,y,z)
2 ---- v(x,z) medium
3 ---- v(z) medium
com_type= computation type, determines what tables are needed
1 ---- only needs traveltime, weight=1.0
2 ---- traveltime, propagation angles, weight=ctheta
3 ---- traveltime, angle and amplitude,
weight = det/as/ag/(1+ctheta)
nzt= number of z samples (1st dimension) in traveltime
nxt= number of x samples (2nd dimension) in traveltime
nyt= number of y samples (3rd dimension) in traveltime
tfile= file containing traveltime array t[nyt][nxt][nzt]
ampfile file containing amplitude array amp[nyt][nxt][nzt]
d21file= file containing Beylkin determinant component array
d22file= file containing Beylkin determinant component array
d23file= file containing Beylkin determinant component array
d31file= file containing Beylkin determinant component array
d32file= file containing Beylkin determinant component array
d33file= file containing Beylkin determinant component array
a1file= file containing ray propagation angle (polar) array
b1file= file containing ray propagation angle (azimuth) array
Optional Parameters:
dt= or from header (dt) time sampling interval of input data
offs= or from header (offset) source-receiver offset
dxm= or from header (d2) x sampling interval of midpoints
fxm=0 first midpoint in input trace
dym=50.0 y sampling interval of midpoints
fym=0 y-coordinate of first midpoint in input trace
nxv= number of x samples (2nd dimension) in velocity
nyv= number of y samples (3rd dimension) in velocity
dxv=50.0 x sampling interval of velocity
fxv=0.0 first x sample of velocity
dyv=50.0 y sampling interval of velocity
fyv=0.0 first y sample of velocity
dzv=50.0 z sampling interval of velocity
fzv=0.0 first z sample of velocity
nxb=nx/2 band centered at midpoints (see note)
fxo=0.0 x-coordinate of first output trace
dxo=15.0 horizontal spacing of output trace
nxo=101 number of output traces ",
fyo=0.0 y-coordinate of first output trace
dyo=15.0 y-coordinate spacing of output trace
nyo=101 number of output traces in y-direction
fzo=0.0 z-coordinate of first point in output trace
dzo=15.0 vertical spacing of output trace
nzo=101 number of points in output trace ",
dxt=100.0 x-coordinate spacing of input tables(traveltime, etc)
dyt=100.0 y-coordinate spacing of input tables(traveltime, etc)
dzt=100.0 z-coordinate spacing of input tables(traveltime, etc)
xt0=0.0 x-coordinate of first input tables
xt1=0.0 x-coordinate of last input tables
yt0=0.0 y-coordinate of first input tables
yt1=0.0 y-coordinate of last input tables
fmax=0.25/dt Maximum frequency set for operator antialiasing
ang=180 Maximum dip angle allowed in the image
apet=45 aperture open angle for summation
alias=0 =1 to set the anti-aliasing filter
verbose=1 =1 to print some useful information
Notes:
The information needed in the computation of the weighting factor
in Kirchhoff inversion formula includes traveltime, amplitude,
and Beylkin determinant at each grid point for each source/receiver
point. For a 3-D nonzero common-offset inversion, the Beylkin
determinant is computed from a 3x3 matrix with each element
containing a sum of quantities from the source and the receiver.
The nine elements in the Beylkin matrix for each source/receiver
can be determined by eight quantities. These quantities can be
computed by the dynamic ray tracer. Tables of traveltime, amplitude,
and Beylkin matrix elements from each source and receiver are
pre-computed and stored in files.
For each trace, tables of traveltime, amplitude and Beylkin matrix
at the source and receiver location are input or interpolated from
neighboring tables. For the computation of weighting factor, linear
interpolation is used to determine the weighting factor at each
output grid point, and weighted diffraction summation is then
applied. For each midpoint, the traveltimes and weight factors are
calculated in the horizontal range of (xm-nxb*dx-z*tan(apet),
xm+nxb*dx+z*tan(apet)).
Offsets are signed - may be positive or negative. ",
This algorithm is based on the inversion formulas in chaper 5 of
_Mathematics of Multimensional Seismic Migration, Imaging and Inversion_
(Springer-Verlag, 2000), by Bleistein, N., Cohen, J.K.
and Stockwell, Jr., J. W.User's notes (Juan Lorenzo) untested
CHANGES and their DATES
Import packages
instantiation of packages
Encapsulated hash of private variables
sub Step
collects switches and assembles bash instructions by adding the program name
sub note
collects switches and assembles bash instructions by adding the program name
sub clear
sub a1file
sub alias
sub ang
sub apet
sub b1file
sub com_type
sub d21file
sub d22file
sub d23file
sub d31file
sub d32file
sub d33file
sub dt
sub dxm
sub dxo
sub dxt
sub dxv
sub dym
sub dyo
sub dyt
sub dyv
sub dzo
sub dzt
sub dzv
sub fmax
sub fxm
sub fxo
sub fxv
sub fym
sub fyo
sub fyv
sub fzo
sub fzv
sub geo_type
sub nxb
sub nxm
sub nxo
sub nxt
sub nxv
sub nym
sub nyo
sub nyt
sub nyv
sub nzo
sub nzt
sub nzv
sub offs
sub tfile
sub verbose
sub vfile
sub weight
sub xt0
sub xt1
sub yt0
sub yt1
sub get_max_index
max index = number of input variables -1