NAME

     minent  - module to do single channel minimum entropy decon-
     volution

SYNOPSIS

     minent [ -Nntap ] [ -Ootap ] [ -Fftap ] [ -sist ] [ -eiend ]
     [  -vvel  ] [ -alfalf ] [ -iiter ] [ -fnfilt ] [ -nsnstr ] [
     -nenetr ] [ -rsnrst ] [ -renred ] [ -U ] [ -V ] [ -? ]

DESCRIPTION

     minent does minimum entropy deconvolution using the  varimax
     norm  calculation  governed  by  the  exponent.  m.e.d. is a
     species of deconvolution requiring no phase assuptions about
     the disturbing function ans seeks a deconvolved output which
     consists of the smallest number of large  spikes  consistent
     with  the  input  data.   -alf4  is  equivalent  to Wiggin's
     minimum entropy decon described in his paper  in  Geophysics
     (no,  I can't remember which issue).  The nonlinear equation
     is solved iteratively for the filter coefficients and previ-
     ous trace's filter is used as the initial guess for the next
     trace.

     minent gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the design window, the start and  end  traces,  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 data  set  name  or  file  immediately
          after typing -O.  This output file is not required when
          piping the output to another process.  The output  data
          set also requires the full path name (see above).

     -F ftap
          Enter the output data set name or file for  the  filter
          output immediately after typing -F.  This output cannot
          be piped as can the filtered output above.   If  no  -F
          entry  is  given  this  output option is ignored in the
          code.

     -alf alf
          Enter the exponent for the varimax norm.  4 =  Wiggin's
          minimum entropy; 2 = least squares.  Default = 4

     -i iter
          Enter the number of iterations (def = 5).  This  number
          should be kepth fairly small to save on machine cycles;
          parameter testing is a good thing to do here.

     -f nfilt
          Enter the length of the filter  in  ms.   There  is  no
          default  but  should  be  kept as low as possible since
          this parameter can run up the  cpu  cost.   In  general
          once  a  certain  length  has  been exceeded no further
          effect will be  seen;  a  parameter  test  should  help
          determine this.

     -s ist
          Enter the start time of the design window.  The default
          is  the  beginning  of  the  trace.  The filter will be
          applied to the whole trace, regardless of the -s and -e
          entries.

     -e iend
          Enter the end time of the design window.   The  default
          is the end of the trace.

     -v vel
          Enter the design window velocity in m or ft/s.  Default
          is  infinite  velocity  or constant start time for each
          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.

     -U   Enter the command line argument '-U' to use the  Ulrych
          exponential  transform  method.   This method can some-
          times prove more efficient especially in  the  presence
          of additive noise.

     -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.

COPYRIGHT

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