<!-- Creator : groff version 1.19.2 -->
<!-- CreationDate: Thu Jan 14 08:19:47 2010 -->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta name="generator" content="groff -Thtml, see www.gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<meta name="Content-Style" content="text/css">
<style type="text/css">
p { margin-top: 0; margin-bottom: 0; }
pre { margin-top: 0; margin-bottom: 0; }
table { margin-top: 0; margin-bottom: 0; }
</style>
<title>MDG77TOGMT</title>
</head>
<body bgcolor="#ffffff">
<h1 align=center>MDG77TOGMT</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#OPTIONS">OPTIONS</a><br>
<a href="#EXAMPLES">EXAMPLES</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<a href="#REFERENCES">REFERENCES</a><br>
<hr>
<a name="NAME"></a>
<h2>NAME</h2>
<p style="margin-left:11%; margin-top: 1em">mgd77togmt
− Convert an MGD-77 ASCII file to a binary gmt
file</p>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<p style="margin-left:11%; margin-top: 1em"><b>mgd77togmt</b>
[ <b>−L</b><i>list</i> ] [ <i>mgd77file</i> ]
<b>−F</b><i>legid</i> <b>−Y</b><i>start_year</i>
[ <b>−A</b><i>information</i> ] [
<b>−I</b><i>time_increment</i> ]
[<b>−T</b>[<i><offset></i>]]
[<b>−W</b>[<i><cable_length></i>]] [
<b>−V</b> ]</p>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<p style="margin-left:11%; margin-top: 1em"><b>mgd77togmt</b>
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, <b>mgd77togmt</b> will
convert those to corrected depths using the Carter tables.
Both old and new (Y2K-compliant) MGD-77 files are
supported.</p>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−L</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Name of file with
several records of the format <i>mgd77file legid
start_year</i>. For multiple files, use this option rather
than the <b>−F −Y</b> combination.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−Y</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">The year of the
first data point in the file. If not provided and -L option
not used, it tries to get it from a header file. The header
file must be in the same directory of the main file and must
have a name equal to the main but with a .h77 extension.</p></td>
</table>
<a name="OPTIONS"></a>
<h2>OPTIONS</h2>
<p style="margin-left:11%; margin-top: 1em">No space
between the option flag and the associated arguments.</p>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−A</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Set an optional 10
character information string to be stored in the header
[Default is blank].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−F</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Leg id that will be
used in file name (<i>legid</i>.gmt). If not given, it will
be constructed from the mgd77file name plus the .gmt
extension.</p> </td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−I</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Used for files
where time is missing. The increment is used to calculate
fake times.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−T</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Extracts Total
field instead of anomaly. Since F does not hold in a 2 byte
signed variable we subtract a constant [default = 40000] but
you can provide another value in <i><offset></i>.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−W</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Take into account
that the magnetometer is not at ship’s position.
<i><cable></i> is magnetometer tow distance [default =
200 meters]. If <b>−W</b> only is given (e.g. no
<cable>) and like with the <b>−Y</b> option, we
try to get the tow distance from the header file. Failing,
defaults to 200 meters. Note that this option will throw
away the first points whose accumulated. distance since the
start of magnetic acquisition is less than cable. length,
and likewise for the end of the mag profile.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−V</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Selects verbose
mode, which will send progress reports to stderr [Default
runs "silently"].</p></td>
</table>
<a name="EXAMPLES"></a>
<h2>EXAMPLES</h2>
<p style="margin-left:11%; margin-top: 1em">To create a gmt
file from the ASCII file c2104.mgd77, run</p>
<p style="margin-left:11%; margin-top: 1em"><b>mgd77togmt</b>
c2104.mgd77 <b>−Y</b>1977</p>
<p style="margin-left:11%; margin-top: 1em">To create new
gmt files from all the mgd77 files listed in
<i>list.d</i>:</p>
<p style="margin-left:11%; margin-top: 1em"><b>mgd77togmt
−L</b>list.d <b>−V</b></p>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<p style="margin-left:11%; margin-top: 1em"><i><A HREF="dat2gmt.html">dat2gmt</A></i>(1),
<i><A HREF="GMT.html">GMT</A></i>(1)</p>
<a name="REFERENCES"></a>
<h2>REFERENCES</h2>
<p style="margin-left:11%; margin-top: 1em">Wessel, P., and
W. H. F. Smith, 2009, The Generic Mapping Tools (GMT)
version 4.5.0 Technical Reference & Cookbook,
SOEST/NOAA. <br>
Wessel, P., and W. H. F. Smith, 1998, New, Improved Version
of Generic Mapping Tools Released, EOS Trans., AGU, 79 (47),
p. 579. <br>
Wessel, P., and W. H. F. Smith, 1995, New Version of the
Generic Mapping Tools Released, EOS Trans., AGU, 76 (33), p.
329. <br>
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. <br>
Wessel, P., and W. H. F. Smith, 1991, Free Software Helps
Map and Display Data, EOS Trans., AGU, 72 (41), p. 441.</p>
<p style="margin-left:11%; margin-top: 1em">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.</p>
<p style="margin-left:11%; margin-top: 1em">Carter, D. J.
T., <i>Echo Sounding Correction Tables: Formerly
Matthews’ Tables</i>, 150 pp, Hydrographic Department,
Ministry of Defense, Taunton, Somerset, England, 1980.</p>
<hr>
</body>
</html>
