SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUMIGFD - 45-90 degree Finite difference depth migration for
zero-offset data.
sumigfd <infile >outfile vfile= [optional parameters]
Required Parameters:
nz= number of depth sapmles
dz= depth sampling interval
vfile= name of file containing velocities
(see Notes below concerning format of this file)
Optional Parameters:
dt=from header(dt) or .004 time sampling interval
dx=from header(d2) or 1.0 midpoint sampling interval
dip=45,65,79,80,87,89,90 Maximum angle of dip reflector
tmpdir= if non-empty, use the value as a directory path
prefix for storing temporary files; else if the
the CWP_TMPDIR environment variable is set use
its value for the path; else use tmpfile()
Notes: ",
The computation cost by dip angle is 45=65=79<80<87<89<90
The input velocity file \'vfile\' 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. (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.) ",
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.
Credits: CWP Baoniu Han, April 20th, 1998
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 dip
sub dt
sub dx
sub dz
sub nz
sub tmpdir
sub vfile
sub get_max_index
max index = number of input variables -1