sunmo

来自「seismic software,very useful」· 代码 · 共 30 行

SUNMO - NMO for an arbitrary velocity function of time and CDP
sunmo <stdin >stdout [optional parameters]
Optional Parameters:
vnmo=2000               NMO velocities corresponding to times in tnmo
tnmo=0                  NMO times corresponding to velocities in vnmo
cdp=0                   CDPs for which vnmo and tnmo are specified
smute=1.5               samples with NMO stretch exceeding smute are zeroed
lmute=25                length (in samples) of linear ramp for stretch mute
sscale=1                =1 to divide output samples by NMO stretch factor
invert=0                =1 to perform (approximate) inverse NMO
Notes:
For constant-velocity NMO, specify only one vnmo=constant.
For NMO with a velocity function of time only, specify the arrays
        vnmo=v1,v2,... tnmo=t1,t2,...
where v1 is the velocity at time t1, v2 is the velocity at time t2, ...
The times specified in the tnmo array must be monotonically increasing.
Linear interpolation and constant extrapolation of the specified velocities
is used to compute the velocities at times not specified.
For NMO with a velocity function of time and CDP, specify the array
        cdp=cdp1,cdp2,...
and, for each CDP specified, specify the vnmo and tnmo arrays as described
above.  The first (vnmo,tnmo) pair corresponds to the first cdp, and so on.
Linear interpolation and constant extrapolation of 1/velocity^2 is used
to compute velocities at CDPs not specified.
NMO interpolation error is less than 1% for frequencies less than 60% of
the Nyquist frequency.
Exact inverse NMO is impossible, particularly for early times at large
offsets and for frequencies near Nyquist with large interpolation errors.
Trace header fields accessed:  ns, dt, delrt, offset, cdp.