NAME

     velloc  - look for time of occurrence of input  velocity  in
     velocity traces

SYNOPSIS

     velloc [ -Nntap ] [ -Ootap ]  [  -wsist  ]  [  -weiend  ]  [
     -vvalue  ] [ -ttol ] [ -hw1hdrwd1 ] [ -hw2hdrwd2 ] [ -nsnstr
     ] [ -nenetr ] [ -rsnrst ] [ -renred ] [ -V ] [ -? ]

DESCRIPTION

     velloc reads a velocity tape data set  and  for  each  input
     trace  looks  for  the  time of first occurrence of an input
     velocity within a window. When this takes  place  two  trace
     header values and the time of occurrence into a flat file.

     velloc gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the search window, the start  and  end  traces,  the  serach
     velocity, and verbose printout, if desired.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing -N unless the input is from a pipe in which case
          the -N entry must be omitted.  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 'dummy' in directory '/b/vsp'.

     -O otap
          Enter the output ascii data set name  or  file  immedi-
          ately  after  typing  -O.   This  output  file  is  not
          required when piping the output to another  process  or
          using  the  UNIX  redirect. The file will contain three
          columns of numbers: first  trace  header  word,  second
          trace   header  word,  time  at  which  the  first  hit
          occurred.

     -ws ist
          Enter the start time of the search window.  The default
          is the beginning of the trace.

     -we iend
          Enter the end time of the search window.   The  default
          is the end of the trace.

     -v value
          Enter the velocity value to search for. No default.

     -t tol
          Enter the % tolerance for the search, i.e.  register  a
          hit  if  the  trace  value  falls within a range + or -
          percent of the user specified value. Default = .1%

     -hw1 hdrwd1
          Enter the first trace header word to use. This is  used
          to identify the trace. Default is to use the sequential
          record counter, e.g. first, second, third, ... record.

     -hw2 hdrwd2
          Enter the second trace header word to use. This is used
          to identify the trace. Default is to use the sequential
          trace counter, e.g. first, second, third, ... trace

     -ns nstr
          Enter the start trace number.  The default is the first
          trace of the record.

     -ne netr
          Enter the end trace number. The  default  is  the  last
          trace of the record.

     -rs nrst
          Enter start record number.  Default value is the  first
          record.

     -re nred
          Enter end record number.  Default value is last record.

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

     -?   Enter the command line  argument  '-?'  to  get  online
          help.   The program terminates after the help screen is
          printed.

EXAMPLE

     If vel.all is a velocity  data  set  that  has  proper  shot
     points  associated  with it then the following is an example
     of extracting times

     velloc -Nvel.all -hw1SoPtNm -hw2TrcNum -ws500 -we1000 -v6500
     -t1 -Ojunk

     where SoPtNm and TrcNum are the two header  words  keyed  on
     and the velocity of 6500 is searched with a tolerance of 1%.

BUGS

     The velocity data set must  have  proper  indexes  if  trace
     header word mnemonics are used.

AUTHOR

     Paul Gutowski

COPYRIGHT

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