NAME

     ich   -  identification  and  characterization  of   seismic
     signal/noise.

SYNOPSIS

     ich [ -Nntap ] [ -Pfile_picks ] [ -Ootap ] [ -f1f1 ] [ -f2f2
     ]  [  -f3f3  ]  [  -f4f4  ]  [  -twtw  ] [ -ttaperttaper ] [
     -smoothnsmooth ] [ -nxtapernxtaper ] [ -S ] [ -M ] [ -V ]  [
     -? ]

DESCRIPTION

     ich for Identification and CHaracterization of seismic  data
     takes  an  xsd  format  pick file corresponding to the input
     seismic data set and outputs a caricature or cartoon of  the
     picked  events  containing  the corresponding trace headers.
     Optionally, one can use the picks to generate a  mask  which
     will then preferentially pass a window of seismic data about
     the picks.

     INPUT:  Input seismic data set and xsd format pick file.

     OUTPUT:  Output caricature or masked version  of  the  input
     seismic data set.

     ich  gets both its data and its parameters from command line
     arguments.   These  arguments specify the input, output, and
     wavelet parameters.

  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'.

     -P file_picks
          Enter  the  input  xsd  format  pick  file   data   set
          corresponding to ntap. No default allowed.

     -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).

     -f1 f1
          Frequency (Hz) at which we begin roll in of  a  Hamming
          zero phase band pass filter (default = 0.1*fnyquist).


     -f2 f2
          Frequency (Hz) at which we end roll  in  of  a  Hamming
          zero phase band pass filter (default = 0.2*fnyquist).

     -f3 f3
          Frequency (Hz) at which we begin roll out of a  Hamming
          zero phase band pass filter (default = 0.9*fnyquist)

     -f4 f4
          Frequency (Hz) at which we end roll out  of  a  Hamming
          zero  phase  band pass filter . The cost increases with
          the value of f4. (default = nyquist).

     -tw tw
          temporal width of wavelet (mask) in msec. (Default = 25
          samples).

     -ttaper ttaper
          temporal taper of wavelet (mask) in msec. (Default =  5
          samples).

     -smooth nsmooth
          perform  nsmooth point smoothing over the picks, honor-
          ing pick boundaries. (Default = 11 points).

     -nxtaper nxtaper
          apply  nxtaper point amplitude tapering at the  segment
          ends. (Default = 0 or no amplitude tapering).

     -S   If present, ignore frequency parameters and generate  a
          spike  on  each trace.  (Default, convolve picks with a
          band limited wavelet defined by  f1,f2,f3,f4).

     -M   If present, form a mask over the input seimic data set.
          (Default,  convolve  picks  with a band limited wavelet
          defined by  f1,f2,f3,f4).

     -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:

     If the line header values SmpInt>16, it is assumed to be  in
     microseconds, rather than in milliseconds.

BUGS

     No bugs known at present.

SEE ALSO

     radonf, radonr, fft2da , rmmult

AUTHOR

     Dennis Bjerstedt (Amoco Canada)  and Kurt J. Marfurt  (APR),
     1992.

COPYRIGHT

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