NAME

     vel2den - Create  a  Density  field  from  velocities  using
     Gardner's Equation

SYNOPSIS

     vel2den [-VELvtap] [-DENdtap] [-nsns]  [-nene]  [-rsirs]  [-
     reire]  [-ascale] [-bexpo] [-wvwatvel] [-met] [-eng] [-V] [-
     svsaltvel] [-sdsaltden] [-?]  [-h]

DESCRIPTION

     vel2den reads a velocity field and creates a  density  field
     using Gardner's equation.  Both the input and output are USP
     formatted datasets.

     vel2den gets both its dataset names and its parameters  from
     command line arguments.

  Command line arguments
     -VELvtap
          Enter the name of the input velocity field after typing
          -VEL.   This  velocity field should be interval veloci-
          ties in depth.  This input file should include the com-
          plete  path  name  if  the  file resides in a different
          directory.  Example -VEL/b/vsp/dummy tells the  program
          to  look  for file 'dummy' in directory 'vsp' stored on
          the 'b' disk. This program expects the header  location
          'Dz1000' to be present in the line header.

     -DENdtap
          Enter the name of the output density field after typing
          -DEN. This dataset also requires the full pathname (see
          above). The densities will  be  output  in  grams/cubic
          centimeter.

     -nsns
          Enter the trace number of the first  trace  to  process
          after  typing  -ns.   The  default  is to use the first
          trace of the record.

     -nene
          Enter the trace number of the  last  trace  to  process
          after typing -ne.  The default is to use the last trace
          of the record.

     -rsirs
          Enter the record number of the first record to  process
          after  typing  -rs.   The  default  is to use the first
          record of the dataset.

     -reire
          Enter the record number of the last record  to  process
          after  typing  -re.   The  default  is  to use the last
          record of the dataset.

     -ascale
          Enter the scaling constant for Gardner's equation after
          typing -a.  The default is .23.

             Gardner's equation:  rho = scale*velocity**expo
                        default:  rho = .23*velocity**.25

     -bexpo
          Enter the exponent for Gardner's equation after  typing
          -b.  The default is .25.

     -wvwatvel
          Enter the velocity of the water after typing -wv.   The
          default is 1480.  When the velocity field is within one
          foot per second of the water velocity, the density  for
          that point will be set to 1.03.

          NOTE:  This velocity must be in the same
                 units as the velocity field.

     -met If this flag is present on the command  line,  it  will
          indicate that the velocity field and the water velocity
          are in metric units.

     -eng If this flag is present on the command  line,  it  will
          indicate that the velocity field and the water velocity
          are in English units.

          NOTE:  Units must be specified on the command line.

     -svsaltvel
          Enter the salt velocity after typing -sv.  This parame-
          ter  is OPTIONAL. If missing from the command line, the
          program will use Gardner's equation  to  calculate  the
          density. If you do specify salt velocity, you must also
          specify the salt density.  See -sd[saltden] explanation
          below.

     -sdsaltden
          Enter the salt density after typing -sd.  This  parame-
          ter  is OPTIONAL. If missing from the command line, the
          program will use Gardner's equation  to  calculate  the
          density.  If you do specify salt density, you must also
          specify the salt velocity.  See  -sv[saltvel]  explana-
          tion above.

     -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

     ppetn, ppdenobg, pptrn, pptrnehz, ppobgmt

BUGS

     None known.

AUTHOR

     Mary Ann Thornton

COPYRIGHT

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