PROCESS SEG2IN
                           ------- ------

Parameters, alphabetically:
ffilen    ftr       ipath     lfilen    lprint    ltr

  Document date: 27 August 1998

       PROCESS SEG2IN reads seismic disk files in the SEG-2 format as
described in the September 1990 Geophysics article "Recommended
standard for seismic (/radar) data files in the personal computer
environment".  Each shot is in a separate disk file.  Data files from
the Geometrics Strataview have been used.
       SEG2IN will handle SEG-2 files that are in little or big endian
byte order.

PARAMETER DICTIONARY
--------- ----------
FFILEN - The first file number (shot) to read from disk.  File numbers
         less than FFILEN will be omitted.  File names are assumed to
         have Geometrics filename.  e.g. nnnn.DAT  where nnnn is the
         shot number.  The file names and shot numbers must be
         monotonically increasing by 1 from FFILEN to LFILEN.  The
         files must be in the current (working) directory.
         Preset = 99999 (none)

LFILEN - The last file number (shot) to read from disk.  File numbers
         greater than LFILEN will be omitted.  
         Preset = 99999 (none)

IPATH  - The input SEG-2 pathname (filename).  The SEG-Y shot number
         will be the value specified by the SEG-2 string 
         SHOT_SEQUENCE_NUMBER if it exists.  If SHOT_SEQUENCE_NUMBER
         does not exist, then the first four digits of IPATH are used,
         assuming the data were recorded on a Geometrics recorder.
         Not used with FFILEN/LFILEN.
         Preset = none    e.g. /usr/people/henkart/data/1019.DAT

FTR    - The first trace in the SEG-2 file to read.  Traces (channels)
         numbered less than FTR will be omitted.
         Preset = 1

LTR    - The last trace in the SEG-2 file to read.  Traces (channels)
         numbered greater than LTR will be omitted.
         Preset = last trace in the file.

LPRINT - Debug print switch.
       = 4, The SEG-2 File Descriptor and the Trace Descriptor strings 
         are printed for EVERY trace between ftr/ltr.

END    - Terminates each parameter list.

EXAMPLE
-------
To read several files that are not strictly monotonically numbered.

seg2in
    ipath /usr/people/henkart/data/1019.DAT end
    ipath /usr/people/henkart/data/1022.DAT end
    ipath /usr/people/henkart/data/1023.DAT end
    ipath /usr/people/henkart/data/1025.DAT end
end


Written by: Paul Henkart, Scripps Institution of Oceanography, August 1998
Copyright (C) The Regents of The University of California
All Rights Reserved.