SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUVELAN_NCCS - compute stacking VELocity panel for cdp gathers

		using Normalized CrossCorrelation Sum 	                     



 suvelan_uccs <stdin >stdout [optional parameters]			     



 Optional Parameters:							     

 nx=tr.cdpt              number of traces in cdp			     

 nv=50                   number of velocities				     

 dv=50.0                 velocity sampling interval			     

 fv=1500.0               first velocity				     

 smute=1.5               samples with NMO stretch exceeding smute are zeroed

 dtratio=5               ratio of output to input time sampling intervals   

 nsmooth=dtratio*2+1     length of smoothing window                         

 verbose=0               =1 for diagnostic print on stderr		     

 pwr=1.0                 semblance value to the power      		     



 Notes:								     

 Normalized CrossCorrelation sum: sum all possible crosscorrelation	     

 trace pairs in a CMP gather for each trial velocity and zero-offset        

 two-way travel time inside a time window. This coherence measure is        

 normalized by dividing each crosscorrelation trace pair by the geometric   

 mean of the energy, inside the chosen time window, of each trace pair      

 involved in each crosscorrelation. Then, to achieve a maximum amplitude    

 of unity, the result is multiplied by  2/(M(M-1)), which is the inverse    

 of the total number of crosscorrelation. The normalization allows to	     

 bring out weak reflection as long as these reflections have moveouts close 

 to a hyperbola.							     





 

 Credits:  



 CWP:  Valmore Celis, Sept 2002	



 Based on the original code: suvelan.c 

    Colorado School of Mines:  Dave Hale, c. 1989



 Trace header fields accessed:  ns, dt, delrt, offset, cdp, cdpt 

 Trace header fields modified:  ns, dt, offset, cdp



 Reference: Neidell, N.S., and Taner, M.T., 1971, Semblance and 

             other coherency measures for multichannel data: 

             Geophysics, 36, 498-509. 

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 fv

sub nsmooth

sub nv

sub nx

sub pwr

sub smute

sub verbose

sub get_max_index

max index = number of input variables -1