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 equal 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.
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.