## NAME

          mgd77togmt - Convert an MGD-77 ascii file to a binary gmt file

## SYNOPSIS

          mgd77togmt [ -Llist ] [ mgd77file ] -Flegid -Ystart_year [
          -Ainformation ] [ -Itime_increment ] [ -V ]

## DESCRIPTION

          mgd77togmt reads an ASCII MGD-77 format file [or standard input] and
          creates a binary gmt file.  The 16 header records specified in the
          MGD-77 documentation may or may not be present.  If two-way travel
          times are available, mgd77togmt will convert those to corrected depths
          using the Carter tables.  Both old and new (Y2K-compiant) MGD-77 files
          are supported.

          -L   Name of file with several records of the format mgd77file legid
               start_year.  For multiple files, use this option rather than the
               -F -Y combination.  -F Leg id that will be used in file name
               (legid.gmt).

          -Y   The year of the first data point in the file

## OPTIONS

          No space between the option flag and the associated arguments.

          -A   Set an optional 10 character information string to be stored in
               the header  [Default is blank].

          -I   Used for files where time is missing.  The increment is used to
               calculate fake times.

          -V   Selects verbose mode, which will send progress reports to stderr
               [Default runs "silently"].

## EXAMPLES

          To create a gmt file from the ASCII file c2104.mgd77, try

          mgd77togmt c2104.mgd77 -Y1977 -Fc2104

          To create new gmt files from all the mgd77-file listed in list.d, try

          mgd77togmt -Llist.d -V

## SEE ALSO

          dat2gmt, gmt

## REFERENCES

          Wessel, P., and W. H. F. Smith, 1999, The Generic Mapping Tools (GMT)
          version 3.2 Technical Reference & Cookbook, SOEST/NOAA.
          Wessel, P., and W. H. F. Smith, 1998, New, Improved Version of Generic
          Mapping Tools Released, EOS Trans., AGU, 79 (47), p. 579.
          Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic
          Mapping Tools Released, EOS Trans., AGU, 76 (33), p. 329.
          Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic
          Mapping Tools Released, http://www.agu.org/eos_elec/95154e.html,
          Copyright 1995 by the American Geophysical Union.
          Wessel, P., and W. H. F. Smith, 1991, Free Software Helps Map and
          Display Data, EOS Trans., AGU, 72 (41), p. 441.

          MGD77 Task Group, 1977, The Marine Geophysical Data Exchange Format -
          'MGD77', Key to Geophysical Records documentation No. 10, National
          Geophysical and Solar-Terrestrial Data Center, Boulder, CO.

          Carter, D. J. T., Echo Sounding Correction Tables: Formerly Matthews'
          Tables, 150 pp, Hydrographic Department, Ministry of Defense, Taunton,
          Somerset, England, 1980.