SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUDMOFK - DMO via F-K domain (log-stretch) method for common-offset gathers
sudmofk <stdin >stdout cdpmin= cdpmax= dxcdp= noffmix= [...]
Required Parameters:
cdpmin= minimum cdp (integer number) for which to apply DMO
cdpmax= maximum cdp (integer number) for which to apply DMO
dxcdp= distance between adjacent cdp bins (m)
noffmix= number of offsets to mix (see notes)
Optional Parameters:
tdmo=0.0 times corresponding to rms velocities in vdmo (s)
vdmo=1500.0 rms velocities corresponding to times in tdmo (m/s)
sdmo=1.0 DMO stretch factor; try 0.6 for typical v(z)
fmax=0.5/dt maximum frequency in input traces (Hz)
verbose=0 =1 for diagnostic print
tmpdir= if non-empty, use the value as a directory path prefix
for storing temporary files; else if the CWP_TMPDIR
environment variable is set use its value for the path;
else use tmpfile()
Notes:
Input traces should be sorted into common-offset gathers. One common-
offset gather ends and another begins when the offset field of the trace
headers changes.
The cdp field of the input trace headers must be the cdp bin NUMBER, NOT
the cdp location expressed in units of meters or feet.
The number of offsets to mix (noffmix) should typically no smaller than
the ratio of the shotpoint spacing to the cdp spacing. This choice
ensures that every cdp will be represented in each offset mix. Traces
in each mix will contribute through DMO to other traces in adjacent cdps
within that mix. (Values of noffmix 2 or 3 times the ratio of shotpoint
spacing to the cdp spacing often yield better results.)
The tdmo and vdmo arrays specify a velocity function of time that is
used to implement a first-order correction for depth-variable velocity.
The times in tdmo must be monotonically increasing.
For each offset, the minimum time at which a non-zero sample exists is
used to determine a mute time. Output samples for times earlier than this",
mute time will be zeroed. Computation time may be significantly reduced
if the input traces are zeroed (muted) for early times at large offsets.
Credits:
CWP: Dave
Technical Reference:
Dip-Moveout Processing - SEG Course Notes
Dave Hale, 1988
Trace header fields accessed: ns, dt, delrt, offset, cdp.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 cdpmax
sub cdpmin
sub dxcdp
sub fmax
sub noffmix
sub sdmo
sub tdmo
sub tmpdir
sub vdmo
sub verbose
sub get_max_index
max index = number of input variables -1