SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES SUVEL2DF - compute stacking VELocity semblance for a single time in
over Vnmo and eta in 2-D
suvel2df <stdin >stdout [optional parameters]
Required Parameters:
tn zero-offset time of reflection
offsetm Maximum offset considered
Optional Parameters:
nv=50 number of velocities
dv=50.0 velocity sampling interval
fv=1500.0 first velocity
nvh=50 number of horizontal velocities
dvh=50.0 horizontal velocity sampling interval
fvh=1500.0 first horizontal velocity
xod=1.5 maximum offset-to-depth ratio to resolve
dtratio=5 ratio of output to input time sampling intervals
nsmooth=dtratio*2+1 length of semblance num and den smoothing window
verbose=0 =1 for diagnostic print on stderr
vavg=fv+0.5*(nv-1)*dv average velocity used in the search
Notes:
Semblance is defined by the following quotient:
n-1
[ sum q(t,j) ]^2
j=0
s(t) = ------------------
n-1
n sum [q(t,j)]^2
j=0
where n is the number of non-zero samples after muting.
Smoothing (nsmooth) is applied separately to the numerator and denominator
before computing this semblance quotient.
Input traces should be sorted by cdp - suvel2df outputs a group of
semblance traces every time cdp changes. Therefore, the output will
be useful only if cdp gathers are input.
Credits:
CWP: Tariq Alkhalifah, February 1997
Trace header fields accessed: ns, dt, delrt, offset, cdp.
Trace header fields modified: ns, dt, offset.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 dtratio
sub dv
sub dvh
sub fv
sub fvh
sub j
sub nsmooth
sub nv
sub nvh
sub vavg
sub verbose
sub xod
sub get_max_index
max index = number of input variables -1