SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUDATUMFD - 2D zero-offset Finite Difference acoustic wave-equation
DATUMing
sudatumfd <stdin > stdout [optional parameters]
Required parameters:
nt= number of time samples on each trace
nx= number of receivers per shot gather
nsx= number of shot gathers
nz= number of downward continuation depth steps
dz= depth sampling interval (in meters)
mx= number of horizontal samples in the velocity model
mz= number of vertical samples in the velocity model
vfile1= velocity file used for thin-lens term
vfile2= velocity file used for diffraction term
dx= horizontal sampling interval (in meters)
Optional parameters:
dt=.004 time sampling interval (in seconds)
buff=5 number of zero traces added to each side of each
shot gather as a pad
tap_len=5 taper length (in number of traces)
x_0=0.0 x coordinate of leftmost position in velocity model
Notes:
The algorithm is a 45-degree implicit-finite-difference scheme based
on the one-way wave equation. It works on poststack (zero-offset)
data only. The two velocity files, vfile1 and vfile2, are binary
files containing floats with the format v[ix][iz]. There are two
potentially different velocity files for the thin-lens and
diffraction terms to allow for the use of a zero-velocity layer
which allows for datuming from an irregular surface.
Source and receiver locations must be set in the header values in
order for the datuming to work properly. The leftmost position of
of the velocity models given in vfile1 and vfile2 must also be given.
Author: Chris Robinson, 10/16/00, CWP, Colorado School of Mines
References:
Beasley, C., and Lynn, W., 1992, The zero-velocity layer: migration
from irregular surfaces: Geophysics, 57, 1435-1443.
Claerbout, J. F., 1985, Imaging the earth's interior: Blackwell
Scientific Publications.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 buff
sub dt
sub dx
sub dz
sub mx
sub mz
sub nsx
sub nt
sub nx
sub nz
sub tap_len
sub vfile1
sub vfile2
sub x_0
sub get_max_index
max index = number of input variables -1