NAME

     horgam - extract  semblances  along  horizons  for  velocity
     analysis.

SYNOPSIS

     horgam [ -Ninput ] [ -Ooutput ] [ -nsns ] [ -nene ] [  -rsrs
     ] [ -rere ] [ -P1inpick ] [ -P2outpick ] [ -dgammadgamma ] [
     -jwinjwin ] [ -jmedjmed ] [ -V ] [ -? ] [ -h ]

DESCRIPTION

     horgam reads the xsd pick file  and  a  usp-compatible  sem-
     blance  depth  file  from xsdprop and outputs both a horizon
     velocity file and an xsd pick file which maps onto the input
     semblance depth file.

     horgam gets both its dataset names and its  parameters  from
     command  line  arguments.  These arguments specify the input
     pick file, the output pick file, the  mbs  data,  the  gamma
     increment, and the window size in samples.

  Command line arguments
     -Nntap
          Enter the input crp sorted gamma scans after typing -N.
          This  file  is  usually  the output from xsdprop.  This
          input file should include the complete path name if the
          file   resides   in  a  different  directory.   Example
          -N/b/vsp/dummy tells the program to look for file  file
          'dummy' in directory 'vsp' stored on the 'b' disk.

     -Ootap
          Enter the output horizon velocity  analysis  file  name
          immediately  after  typing -O.  Each output record will
          correspond to an input pick segment.  Each  input  pick
          segment  will correspond to a horizon.  The output hor-
          izon velocity file requires the  full  path  name  (see
          above).

     -rsrs
          Enter the starting record number after typing -rs.

     -rere
          Enter the ending record number after typing -re.

     -nsns
          Enter the starting trace after type -ns.

     -nene
          Enter the ending trace after type -ne.

     -P1inpick
          Enter the input xsd pick file  name  immediately  after
          typing  -P1.   This  file  should  have been created by
          program xsdintrp on an xsd segment file.  Sometimes  it
          is convenient to use programs xsdd2t followed by xsdt2d
          to  convert  from  one   depth   to   another   between
          mbs/tomography iteration sequences.  The input xsd pick
          file also requires the full path name (see above).

     -P2outpick
          Enter the output xsd pick file name  after  typing  -O.
          Each output segment will correspond to an input record.
          The output file also requires the full path  name  (see
          above).   The "StaCor" value in the output trace header
          will contain the sample number of  the  picked  horizon
          which  corresponds  to the output record.  The "DstSgn"
          value in the output trace header will contain the  out-
          put  sample  number  of  the  picked gamma.  The picked
          value will be a negative value in the output data so it
          will stand out when you plot it with xsd.

     -dgammadgamma
          Enter the increment  between  gammas.   The  number  of
          gamma scans is equal to the number of traces per record
          on input  which  is  equal  to  the  number  of  binned
          offsets.   The default is 0.020.  If you have 30 traces
          per record, then the default gamma scans will be +/- 30
          percent because 15 (30/2) times .020 is .30.

     -jwinjwin
          Enter the number of samples in both the  search  window
          for  maximum  semblance  peak.   The output data is the
          average of the data within the search window.   Default
          is 5.

     -jmedjmed
          Enter the  number  of  samples  in  the  median  filter
          applied  to  the  picks  after  picking the gamma.  The
          default is 3.

     -V   Enter the command line argument '-V' to get  additional
          printout.

     -?   Enter this (or '-?' if you are running in  c-shell)  to
          get  online  help.   The  program  will terminate after
          printing this.

     -h   Enter this option to get online help.  The program will
          terminate after printing this.

SEE ALSO

     xsdd2t, xsdt2d, xsdprop, xsdintrp, xsd2xtpick, appgam.

BUGS

     Unknown

AUTHOR

     Gary Murphy

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.