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lib/App/SeismicUnixGui/sunix/datum/sukdmdcr.pm  view on Meta::CPAN

package App::SeismicUnixGui::sunix::datum::sukdmdcr;

=head2 SYNOPSIS

PERL PROGRAM NAME: 

AUTHOR: Juan Lorenzo (Perl module only)

DATE:

DESCRIPTION:

Version:

=head2 USE

=head3 NOTES

=head4 Examples

=head2 SYNOPSIS

=head3 SEISMIC UNIX NOTES
  SUKDMDCR - 2.5D datuming of receivers for prestack, common source    

            data using constant-background data mapping formula.       

            (See selfdoc for specific survey requirements.)            



    sukdmdcr  infile=  outfile=  [parameters] 	         		



 Required file parameters:						

 infile=stdin		file for input seismic traces			

 outfile=stdout	file for output          			

 ttfile=		file for input traveltime tables		



 Required parameters describing the traveltime tables:		        

 fzt= 			first depth sample in traveltime table		

 nzt= 			number of depth samples in traveltime table	

 dzt=			depth interval in traveltime table		

 fxt=			first lateral sample in traveltime table	

 nxt=			number of lateral samples in traveltime table	

 dxt=			lateral interval in traveltime table		

 fs= 			x-coordinate of first source in table		

 ns= 			number of sources in table			

 ds=			x-coordinate increment of sources in table	



 Parameters describing the input data:                                 

 nxso=                  number of shots                                 

 dxso=                  shot interval                                   

 fxso=0                x-coordinate of first shot                      

 nxgo=                  number of receiver offsets per shot             

 dxgo=                  receiver offset interval                        

 fxgo=0                first receiver offset                           

 dt= or from header (dt)       time sampling interval of input data    

 ft= or from header (ft)       first time sample of input data         

lib/App/SeismicUnixGui/sunix/datum/sukdmdcr.pm  view on Meta::CPAN

   

 1. Input traces must be SU format and organized in common shot gathers.



 2. Traveltime tables were generated by program rayt2d (or equivalent)     

    on any grid, with dimension ns*nxt*nzt. In the extrapolation process,       

    traveltimes are interpolated into shot/geophone locations and     

    output grids.                                          



 3. If the offset value of an input trace is not in the offset array     

    of output, the nearest one in the array is chosen.                   



 4. Amplitudes are computed using the constant reference wavepeed v0.

                                

 5. Input traces must specify source and receiver positions via the header  

    fields tr.sx and tr.gx.             



 6. Recording and datuming surfaces are defined as follows:  If recording

    surface is horizontal, set recsurf=0 (default).  Then, zrec will be a

    required parameter, set to the depth of surface.  If the recording  

    surface is topographic, then set recsurf=1.  Then, recfile is a required

    input file.  The input file recfile should be a single column ascii file

    with the depth of the recording surface at every surface location (first 

    source to last offset), with spacing equal to dxgo. 

 

    The same holds for the datuming surface, using datsurf, zdat, and datfile.





 Assumptions and limitations:



 1. This code implements a 2.5D extraplolation operator that allows to

    transfer data from one reference surface to another.  The formula used in

    this application is an adaptation of Bleistein & Jaramillo's 2.5D data

    mapping formula for receiver extrapolation.  This is the result of a

    stationary phase analysis of the data mapping equation in the case of

    a constant source location (shot gather). 

 



 Credits:

 

 Authors:  Steven D. Sheaffer (CWP), 11/97 





 References:  Sheaffer, S., 1999, "2.5D Downward Continuation of the Seismic

              Wavefield Using Kirchhoff Data Mapping."  M.Sc. Thesis, 

              Dept. of Mathematical & Computer Sciences, 

              Colorado School of Mines.







=head2 User's notes (Juan Lorenzo)
untested

=cut


=head2 CHANGES and their DATES

=cut

use Moose;
our $VERSION = '0.0.1';


=head2 Import packages

=cut

use aliased 'App::SeismicUnixGui::misc::L_SU_global_constants';

use App::SeismicUnixGui::misc::SeismicUnix qw($in $out $on $go $to $suffix_ascii $off $suffix_su $suffix_bin);
use aliased 'App::SeismicUnixGui::configs::big_streams::Project_config';


=head2 instantiation of packages

=cut