SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUMIGPREFFD - The 2-D prestack common-shot Fourier finite-difference
depth migration.
sumigpreffd <indata >outfile [parameters] ",
Required Parameters: ",
nxo= number of total horizontal output samples
nxshot= number of shot gathers to be migrated
nz= number of depth sapmles
dx= horizontal sampling interval
dz= depth sampling interval
vfile= velocity profile, it must be binary format.
Optional Parameters:
fmax=25 the peak frequency of Ricker wavelet used as source wavelet
f1=5
f2=10
f3=40
f4=50 frequencies to build a Hamming window
lpad=9999
rpad=9999 number of zero traces padded on both
sides of depth section to determine the
migration aperature, the default
values are using the full aperature.
verbose=0 silent, =1 additional runtime information
Notes:
The input velocity file consists of C-style binary floats. ",
The structure of this file is vfile[iz][ix]. Note that this means that
the x-direction is the fastest direction instead of z-direction! Such a
structure is more convenient for the downward continuation type
migration algorithm than using z as fastest dimension as in other SU ",
programs.
Because most of the tools in the SU package (such as unif2, unisam2, ",
and makevel) produce output with the structure vfile[ix][iz], you will
need to transpose the velocity files created by these programs. You may
use the SU program \'transp\' in SU to transpose such files into the
required vfile[iz][ix] structure.
(In C v[iz][ix] denotes a v(x,z) array, whereas v[ix][iz]
denotes a v(z,x) array, the opposite of what Matlab and Fortran
programmers may expect.) ",
Also, sx must be monotonically increasing throughout the dataset, and
and gx must be monotonically increasing within a shot. You may resort
your data with \'susort\', accordingly.
The scalco header field is honored so this field must be set correctly.
See selfdocs of \'susort\', \'suchw\'. Also: sukeyword scalco
Credits: CWP, Baoniu Han, bhan@dix.mines.edu, April 19th, 1998
Modified: Chris Stolk, 11 Dec 2005, - changed data input
to remove erroneous time delay.
Modified: CWP, John Stockwell 26 Sept 2006 - replaced Han's
"goto-loop" with "do { }while loops".
Fixed it so that sx, gx, and scalco are honored.
Trace header fields accessed: ns, dt, delrt, d2
Trace header fields modified: ns, dt, delrtUser'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 dx
sub dz
sub f1
sub f2
sub f3
sub f4
sub fmax
sub lpad
sub nxo
sub nxshot
sub nz
sub rpad
sub verbose
sub vfile
sub get_max_index
max index = number of input variables -1