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  argu-
     ments.

     -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.