NAME

     notch  - do notch filtering

SYNOPSIS

     notch [ -Nntap ] [ -Ootap ] [ -fnifn ] [ -wniwn ] [  -pwipow
     ]  [  -harmiharm  ] [ -rfsifrs ] [ -rfeifre ] [ -tfsifts ] [
     -tfeifte ] [ -xmindist ] [ -xmaxdist ] [ -V ] [ -? ]

DESCRIPTION

     notch comuutes and applies a simple zero phase notch  filter
     to seismic data

     notch gets both its data and  its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the traces/records to process  (the  rest  of  the  data  is
     passed  through),  the  notch  frequency  and 1/2 width, the
     notch power factor, and the number of harmonics of the  fun-
     damental to nail.

  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).

     -fn ifn
          Enter the center frequency of the notch (Hz).   Default
          = 60

     -wn iwn
          Enter the 1/2 width of the notch (Hz).  Default = 3

     -pw ipow
          Enter the power factor of the filter, i.e the number of
          times to apply the filter.  Default = 1

     -harm iharm
          Enter the number of harmonics of ifn to nail  in  addi-
          tion to the fundamental.  Default = 0

     -tfs ifts
          Enter the start trace number to filter. The default  is
          the  first  trace of each record. Data below this limit
          will be passed unprocessed.  This number is sequential.

     -tfe ifte
          Enter endt trace number to filter.   Default  value  is
          the  last  trace  in each record. Data above this limit
          will be passed unprocessed.  This number is sequential.

     -rfs ifrs
          Enter start record number to filter.  Default value  is
          first  record.   Data  below  this limit will be passed
          unprocessed.  This number is sequential.

     -rfe ifre
          Enter end record number to filter.   Default  value  is
          last  record.   Data  above  this  limit will be passed
          unprocessed.  This number is sequential.

     -xmin dist
          Enter minimum trace distance to filter.  Default  value
          is  -9999999.0.   Data  below this limit will be passed
          unprocessed.

     -xmax dist
          Enter maximum trace distance to filter.  Default  value
          is  9999999.0.   Data  above  this limit will be passed
          unprocessed.

     -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.

BUGS

     unknown

AUTHOR

     Dennis Bjerstedt, Amoco Canada

COPYRIGHT

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