NAME

     polymute  - generalized polygonal mute with 2D tapers.

SYNOPSIS

     polymute [ -N ntap ] [ -O otap ] [ -M response ]  [  -reject
     reject ] [ -nxtaper nxtaper ] [ -nztaper nztaper ] [ -rs irs
     ] [ -re ire ] [ -force ] [ -replace ] [ -value value ] [  -V
     ] [ -? -h or -help ]

DESCRIPTION

     polymute in the default mode mutes data outside  a  smoothly
     tapered  user  defined polygon in xsd format. Unlike the usp
     programs mute and bdmute which apply mute tapers in only the
     trace  direction,  the  2D tapers implicit in polymute allow
     the user to effectively mute data in  the  f-k,  tau-p,  and
     radon  domains.  It  can also be used in the X-T domain how-
     ever.  Polygons can be picked at  control  records  along  a
     line and will smoothly morph the polygons between these con-
     trol records at application time. Be sure the record numbers
     in  your  xsd pick segments correspond to those on the input
     data (it picked on a data subset from say, editt,  you  need
     to  save  the  pick  file  with  the proper record units and
     offset).  The user may optionally replace amplitudes in  the
     mute zone with a user defined value from the command line.

     The smoothed polygonal mute  pattern  is  interpolated  from
     record  to  record, allowing the user to attack noise trains
     that vary significantly across the seismic line.

     polymute gets both its data and its parameters from  command
     line  arguments.   These  arguments specify the input, taper
     options, amplitude replacement options  and mute application
     mode.

  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).

     -P pickfile
          Enter the input xsd format pick file  name  immediately
          after  typing  -P.  polymute  will linearly interpolate
          polygonal mutes defined by the xsd  pick  file  to  the
          value  stored in the seismic trace header RecNum value.
          (no default).

     -nxtaper nxtaper
          Enter the taper length in the horizontal (trace) direc-
          tion  in  number  of traces. (e.g. kx direction for f-k
          transforms, p direction for tau-p transforms)  (Default
          = 10).

     -nztaper nztaper
          Enter the taper length in the vertical (sample)  direc-
          tion  in  number  of  samples (e.g. f direction for f-k
          transforms, tau direction for tau-p transforms)  Tapers
          approach  their  50%  reject  along  the  edges  of the
          polygons. (Default = 10).

     -rs irs
          Enter the record number (RecNum) to start muting.  This
          will  not  affect  interpolation between picks just the
          start of the muting process.  Default = first record

     -re ire
          Enter the record number (RecNum) to  end  muting.  This
          will  not  affect  interpolation between picks just the
          end of the muting process.  Default = last record

     -M response
          Enter 'in' to mute inside the polygon,  'out'  to  mute
          outside the polygon. (Default = 'out')

     -reject reject
          Enter percent noise rejection in the  muted  zone  that
          lies beyond the taper edges (Default=100%).

     -replace
          If present on the command line the routine will replace
          amplitudes  in the mute zone with a user defined ampli-
          tuded entered using -value[] below.  The default is  to
          place hard zeroes in the mute zone.

     -value value
          Enter the amplitude desired  in  the  mute  zone.   The
          default is a hard zero [0.00].

     -force
          Enter the  command  line  argument  '-force'  to  force
          polymute  to  mute  past  the base frequency on fourier
          transform data.  Both fft2da and fft3da flat the output
          line  header  as  transformed  data.  Polymute, when it
          sees this flag assumes the trace to be made up of  both
          amplitude,  at the top, and phase, at the bottom, data.
          In the case where you have transposed fft3da  data  for
          filtering,  the  presence of this flag will prevent you
          from being able to mute the last half  of  your  trace.
          The use of this flag will enable you to mute the entire
          trace if desired.  WARNING: Do Not use -force  on  data
          as  output  by  fft2da or polymute will be able to mute
          data in the phase portion of the dataset."

     -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.

NOTE 1

     The piped flow  fft2da|polymute|fft2da -R  allows  the  user
     much greater flexibility (and danger!) than the more conven-
     tional temporal (sctvf) and fan filtering techniques (dipf).

NOTE 2

     The piped flow  taupf|polymute|taupr -R should also be  con-
     sidered.

SEE ALSO:

     fft2da, radonf, radonr, bdmute

AUTHOR

      Kurt J. Marfurt, APR (1992).
      Mods P.G.A. Garossino Nov (1994), Feb (1999)