SUXCOR - correlation with user-supplied filter

suxcor <stdin >stdout filter= [optional parameters]

Required parameters: ONE of
sufile= file containing SU traces to use as filter
filter= user-supplied correlation filter (ascii)

Optional parameters:
first=1 supplied trace is default first element of
correlation. =0 for it to be second.
panel=0 use only the first trace of sufile as filter
=1 xcor trace by trace an entire gather
ftwin=0 first sample on the first trace of the window
(only with panel=1)
ltwin=0 first sample on the last trace of the window
(only with panel=1)
ntwin=nt number of samples in the correlation window
(only with panel=1)
ntrc=48 number of traces on a gather
(only with panel=1)

Trace header fields accessed: ns
Trace header fields modified: ns

Notes: It is quietly assumed that the time sampling interval on the single trace and the output traces is the same as that on the traces in the input file. The sufile may actually have more than one trace, but only the first trace is used when panel=0. When panel=1 the number of traces in the sufile MUST be the same as the number of traces in the input.

Examples:
suplane | suwind min=12 max=12 >TRACE
suxcor<DATA sufile=TRACE |...
Here, the su data file, "DATA", is correlated trace by trace with the single su trace, "TRACE".

suxcor<DATA filter=1,2,1 | ...
Here, the su data file, "DATA", is correlated trace by trace with the filter shown.

Correlating vibroseis data with a vibroseis sweep:
suxcor < data sufile=sweep |
suwind itmin=nsweep itmax=nsweep+nsout | sushw key=delrt a=0.0 |...

sweep=vibroseis sweep in SU format, nsweep=number of samples on
the vibroseis sweep, nsout=desired number of samples on output

or
suxcor < data sufile=sweep |
suwind itmin=nsweep itmax=nsweep+nsout | sushw key=delrt a=0.0 |...

tsweep=sweep length in seconds, tout=desired output trace length in seconds

In the spatially variant case (panel=1), a window with linear slope can be defined:
ftwin is the first sample of the first trace in the gather,
ltwin is the first sample of the last trace in the gather,
ntwin is the lengthe of the window,
ntrc is the the number of traces in a gather.

If the data consists of a number gathers which need to be correlated with the same number gathers in the sufile, ntrc assures that the correlating window re-starts for each gather.

The default window is non-sloping and takes the entire trace into account (ftwin=ltwin=0, ntwin=nt).


Credits:
CWP: Jack K. Cohen, Michel Dietrich
CWP: modified by Ttjan to include cross correlation of panels
permitting spatially and temporally varying cross correlation.

CAVEATS:
In the option, panel=1 the number of traces in the sufile must be
the same as the number of traces on the input.

Trace header fields accessed: ns
Trace header fields modified: ns