SYNOPSIS

PERL PROGRAM NAME:

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

USE

NOTES

Examples

SYNOPSIS

SEISMIC UNIX NOTES SUMIGPRESP - The 2-D prestack common-shot split-step Fourier ",

		migration 						



   sumigpresp <indata >outfile [parameters]				", 



 Required Parameters:							

 nxo=	   number of total horizontal output samples			

 nxshot=	number of shot gathers to be migrated			

 nz=	    number of depth sapmles					

 dx=	    horizontal sampling interval				

 dz=	    depth sampling interval					

 vfile=	 velocity profile, it must be binary format.		

  

 Optional Parameters:						   	

 fmax=25	The peak frequency of Ricker wavelet used as source wavelet

 f1=

 f2=10

 f3=40

 f4=50	 frequencies to build a Hamming window	

 lpad=9999

 rpad=9999	    number of zero traces padded on both    	

				sides of depth section to determine the 

				migration aperature, the default values 

				are using the full aperature.		

 verbose=0             silent, =1 additional runtime information       

  

 Notes:								

 The input velocity file 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.								



 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.					

 (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.)						", 



 Also, sx must be monotonically increasing throughout the dataset, and 

 and gx must be monotonically increasing within a shot. You may resort 

 your data with \'susort\', accordingly.                               



 The scalco header field is honored so this field must be set correctly.

 See selfdocs of \'susort\', \'suchw\'. Also:   sukeyword scalco       







 Credits: CWP, Baoniu Han, bhan@dix.mines.edu, April 19th, 1998

          Modified: Chris Stolk, 11 Dec 2005, - changed data input

                    to remove erroneous time delay.

          Modified: CWP, John Stockwell 26 Sept 2006 - replaced Han's

          "goto-loop" in two places with "do { }while loops".

          Fixed it so that sx, gx, and scalco are honored.





 Trace header fields accessed: ns, dt, delrt, d2, sx, gx, scalco

 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 dx

sub dz

sub f2

sub f3

sub f4

sub fmax

sub lpad

sub nxo

sub nxshot

sub nz

sub rpad

sub verbose

sub vfile

sub get_max_index

max index = number of input variables -1