/ 
App-SeismicUnixGui-0.87.2
River stage zero No dependents
/ App::SeismicUnixGui::sunix::migration::sumigffd

SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUMIGFFD - Fourier finite difference depth migration for

	    zero-offset data. This method is a hybrid migration which	

	    combines the advantages of phase shift and finite difference", 

	    migrations.							



 sumigffd <infile >outfile vfile= [optional parameters]		



 Required Parameters:						  	

 nz=		   number of depth sapmles			 	", 

 dz=		   depth sampling interval			 	

 vfile=		name of file containing velocities	      	



 Optional Parameters:						  	

 dt=from header(dt) or .004    time sampling interval		  	

 dx=from header(d2) or 1.0     midpoint sampling interval	  	

 ft=0.0			first time sample			

 fz=0.0			first depth sample		      	



 tmpdir=	if non-empty, use the value as a directory path		

		prefix for storing temporary files; else if the		

		the CWP_TMPDIR environment variable is set use		

		its value for the path; else use tmpfile()		

 

 The input velocity file \'vfile\' consists of C-style binary floats.  ",  

 The structure of this file is vfile[iz][ix]. Note that this means that

 the x-direction is the fastest direction instead of z-direction! Such a

 structure is more convenient for the downward continuation type	

 migration algorithm than using z as fastest dimension as in other SU  ", 

 programs. (In C  v[iz][ix] denotes a v(x,z) array, whereas v[ix][iz]  

 denotes a v(z,x) array, the opposite of what Matlab and Fortran	

 programmers may expect.)						", 



 Because most of the tools in the SU package (such as  unif2, unisam2, ", 

 and makevel) produce output with the structure vfile[ix][iz], you will

 need to transpose the velocity files created by these programs. You may

 use the SU program \'transp\' in SU to transpose such files into the  

 required vfile[iz][ix] structure.					









 Credits: CWP Baoniu Han, July 21th, 1997





 Trace header fields accessed: ns, dt, delrt, d2

 Trace header fields modified: ns, dt, delrt

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 dt

sub dx

sub dz

sub ft

sub fz

sub nz

sub tmpdir

sub vfile

sub get_max_index

max index = number of input variables -1