NAME

     matchf - match filter removal of surface/dispersed waves

SYNOPSIS

     matchf [ -Nntap ] [ -Ootap ] [ -vnamev ] [ -rere ] [ -rsrs ]
     [  -nsns ] [ -nene ] [ -ulul ] [ -uuuu ] [ -fufu ] [ -flfl ]
     [ -t0t0 ] [ -x0x0 ] [ niterniter ] [ -V ] [ -? ]

DESCRIPTION

     matchf applies a data refined matched filter to reject  sur-
     face wave arrivals on a trace-by-trace basis. The input con-
     sists of a rough guess  of  the  group  velocity  dispersion
     curve,  ul(fl)  and  uu(fu).  These group velocity-frequency
     pairs  define  parallelogram   rejection   zone   in   group
     velocity-frequency  space so it very useful to look first at
     the data using pomega.  This rejection  zone  can  be  moved
     around the seismic record by using the x0 and t0 parameters.
      The program fits the original data (in the process arriving
     at  a  dispersion  curve for a particular mode it has locked
     on) and the improved estimated  using  a  cubic  spline.   A
     total  of  niter iterations are used to improve the estimate
     of the phase velocity dispersion curve.

     If a -v flag followed by a file name is given then the final
     dispersion curve is written into that file in a format suit-
     able with a little editing for input to surface wave  inver-
     sion  (extraction of shear wave velocity vs. depth, at least
     for the shallow subsurface).

  Command line arguments
     -N ntap
          Enter the full path of the  file  continuing  the  data
          set.  If  not specified, input is expected on the stan-
          dard input. If standard input  is  not  specified,  and
          there  is  no  input,  e.g., program run in background,
          expect a  very  ungracious  crash.   (default  standard
          input)

     -O otap
          Enter the full path of the file containing the process-
          ing output.

     -v namev
          Enter  the  name  of  the  dispersion  curve  file  (if
          desired).

     -rs rs
          (integer) Give the first record for processing (default
          = 1)

     -re re
          (integer) Give the last record for processing  (default
          = last)

     -ns ns
          (integer)  Define  the  starting  trace  for   analysis
          (default = 1)

     -ne ne
          (integer) Define the last trace for  analysis  in  each
          record (default = ns) The use of the ns and ne pair are
          useful to be able to skip dead traces or to select just
          a portion of the data set for analysis

     -uu uu
          Upper group velocity estimate at fmax. The group  velo-
          city  window  in  affect defines the time window on the
          original trace affected by the  matched  filter  opera-
          tion.  (default = 10,000)

     -ul ul
          Group velocity at fmin (default = 1000.0)

     -fu fu
          Defines the frequency  corner (in hz) corresponding  to
          the higher uu group velocity (default = 5 )

     -fl fl
          Defines the frequency corner corresponding to the lower
          ul group velocity (default = 20 )

     -niter niter
          Number of iterations used to refine the  phase  matched
          filter for each trace.  (default = 3 ).

     -x0, -t0 x0, -t0
          Shift the effects of matchf to start at a certain  dis-
          tance  in  ft  or  m  (x0)  and  time  in ms (t0).  The
          filtering process is symmetric about the x0  value  and
          is  constrained  to  begin at the t0 value and not ear-
          lier.  (defaults = 0.0 and 0.0 ).

     -V   Flag for verbose output on the  standard  output.  This
          lists  salient  trace header information as well as all
          command values used for processing,  the  default  ones
          given if not overridden.

     -?   Query  mode.   With  this  flag,  matchf  will  give  a
          description  of the command line arguments and stop the
          program.

SEE ALSO

AUTHOR

     R. B. Herrmann and D. R. Russell,  Saint  Louis  University,
     July 1986.

COPYRIGHT

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