. ./utils.sh
OPTION=`lookupkey "$QUERY_STRING" option`
if test "$OPTION" = Reset; then
INPUT=
else
INPUT=`lookupcheckkey "$QUERY_STRING" input`
ZONE=`lookupkey "$QUERY_STRING" zone`
PREC=`lookupkey "$QUERY_STRING" prec`
fi
test "$ZONE" || ZONE=-3
test "$PREC" || PREC=0
INPUTENC=`encodevalue "$INPUT"`
EXECDIR=../bin
COMMAND="GeoConvert"
VERSION=`$EXECDIR/$COMMAND --version | cut -f4 -d" "`
F='<font color="Blue">'
G='</font>'
test $PREC = 0 || COMMAND="$COMMAND -p $PREC"
LOCG=
LOCD=
LOCU=
LOCM=
GEOH=
set -o pipefail
if test "$INPUT"; then
LOCG=`echo $INPUT | $EXECDIR/$COMMAND | head -1`
if test $? -eq 0; then
GEOH=`echo $INPUT | $EXECDIR/$COMMAND -p 1 | head -1`
LOCG=`geohack $GEOH $LOCG Blue`
LOCD=\(`echo $INPUT | $EXECDIR/$COMMAND -d | head -1`\)
case $ZONE in
-3 ) ;;
-2 ) COMMAND="$COMMAND -t";;
-1 ) COMMAND="$COMMAND -s";;
* ) COMMAND="$COMMAND -z $ZONE"
esac
LOCU=`echo $INPUT | $EXECDIR/$COMMAND -u | head -1`
LOCM=`echo $INPUT | $EXECDIR/$COMMAND -m | head -1`
fi
fi
echo Content-type: text/html
echo
cat <<EOF
<html>
<head>
<title>
Online geographic coordinate converter
</title>
<meta name="description"
content="Online geographic coordinate converter" />
<meta name="author" content="Charles F. F. Karney" />
<meta name="keywords"
content="geographic coordinate conversions,
geographic coordinates,
latitude and longitude,
degrees minutes seconds,
universal transverse Mercator, UTM,
easting northing and zone,
universal polar sterographic, UPS,
military grid reference system, MGRS,
online calculator,
WGS84 ellipsoid,
GeographicLib" />
</head>
<body>
<h3>
Online geographic coordinate conversions using the
<a href="https://geographiclib.sourceforge.io/C++/doc/GeoConvert.1.html">
GeoConvert</a> utility
</h3>
<form action="/cgi-bin/GeoConvert" method="get">
<p>
Location
(ex. «<tt>33.33 44.4</tt>»,
«<tt>33d19'47"N 44d23.9'E</tt>»,
«<tt>38SMB4488</tt>»,
«<tt>38n 444000 3688000</tt>»):<br>
<input type=text name="input" size=40 value="$INPUTENC">
</p>
<table>
<tr>
<td>
Output zone:<br>
<select name="zone" size=1>
EOF
(
cat <<EOF
-3 Match input or standard
-1 Standard UPS/UTM zone
0 UPS
-2 Standard UTM zone
EOF
) | while read z name; do
SELECTED=
test "$z" = "$ZONE" && SELECTED=SELECTED
echo "<option $SELECTED value=\"$z\">$name</option>"
done
for ((z=1; z<=60; ++z)); do
SELECTED=
test "$z" = "$ZONE" && SELECTED=SELECTED
name="UTM zone $z"
echo "<option $SELECTED value=\"$z\">$name</option>"
done
cat <<EOF
</select>
</td>
<td>
Output precision:<br>
<select name="prec" size=1>
EOF
(
cat <<EOF
-5 100km 1d
-4 10km 0.1d
-3 1km 0.01d 1'
-2 100m 0.001d 0.1'
-1 10m 0.0001d 1"
0 1m 0.00001d 0.1"
1 100mm 0.01"
2 10mm 0.001"
3 1mm 0.0001"
4 100um 0.00001"
5 10um 0.000001"
6 1um 0.0000001"
7 100nm 0.00000001"
8 10nm 0.000000001"
9 1nm 0.0000000001"
10 0.00000000001"
EOF
) | while read p desc; do
SELECTED=
test "$p" = "$PREC" && SELECTED=SELECTED
echo "<option $SELECTED value=\"$p\">$desc</option>"
done
cat <<EOF
</select>
</td>
</tr>
</table>
<p>
Select action:<br>
<input type="submit" name="option" value="Submit">
<input type="submit" name="option" value="Reset">
</p>
<p>
Results:
<font size="4"><pre>
input = `encodevalue "$INPUT"`
lat lon = $F$LOCG `convertdeg "$LOCD"`$G
<a href="https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system">UTM</a>/<a href="https://en.wikipedia.org/wiki/Universal_Polar_Stereographic">UPS</a> = $F`encodevalue "$LOCU"`$G
<a href="https://en.wikipedia.org/wiki/Military_grid_reference_system">MGRS</a> = $F`encodevalue "$LOCM"`$G</pre></font>
</p>
</form>
<hr>
<p>
<a href="https://geographiclib.sourceforge.io/C++/doc/GeoConvert.1.html">
GeoConvert (version $VERSION)</a>
converts between geographic (latitude and longitude) coordinates,
<a href="https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system">
universal transverse Mercator (UTM)</a> or
<a href="https://en.wikipedia.org/wiki/Universal_Polar_Stereographic">
universal polar stereographic (UPS)</a> coordinates, and the
<a href="https://en.wikipedia.org/wiki/Military_grid_reference_system">
military grid reference system (MGRS)</a>.
Examples of legal geographic locations are (these all refer to roughly
the same place, Cape Morris Jesup on the northern tip of Greenland):
<pre>
Latitude and longitude: MGRS:
83.627 -32.664 24XWT783908
W32d40 N83d37.6 YUB17770380
83°37'39"N 32°39'52"W UTM:
83:37:39 32:39:52W 25n 504158 9286521
32:39.9W 83:37.6N 430000 9290000 26n
32:40W+0:0:6 83:37.6 UPS:
32:40W+0:0:6 83:38-0:0.4 n 1617772 1403805</pre>
<b>Notes:</b>
<ul>
<li>
The letter in following the zone number in the UTM position is
a hemisphere designator (n or s) and <em>not</em> the MGRS
latitude band letter. "north" or "south" can also be used,
e.g., 25north.
<li>
MGRS coordinates are taken to refer to <em>grid squares</em>
(<em>not</em> to the intersections of grid lines). Thus in UTM
zone 38n, the square area with easting in [444 km, 445 km) and
northing in [3688 km, 3689 km) corresponds to the MGRS square
38SMB4488 (at 1 km precision).
<ul>
<li>
When an MGRS coordinate is read, a representative point
within the grid square, namely, the <em>center</em>, is
returned.
<li>
The MGRS easting and northing are obtained
by <em>truncation</em> to the requested precision
(<em>not</em> rounding).
</ul>
<li>
Usually <em>Output zone</em> should be <em>Match input or
standard</em>. If the latitude and longitude are given, the
standard UPS and UTM zone rules are applied; otherwise the
UPS/UTM selection and the UTM zone match the input. The other
choices let you override this selection.
</ul>
</p>
<p>
<a href="https://geographiclib.sourceforge.io/C++/doc/GeoConvert.1.html">
GeoConvert</a>,
which is a simple wrapper of the
<a href="https://geographiclib.sourceforge.io/C++/doc/classGeographicLib_1_1GeoCoords.html">
GeographicLib::GeoCoords</a> class,
is one of the utilities provided
with <a href="https://geographiclib.sourceforge.io/">
GeographicLib</a>.
This web interface illustrates a subset of its capabilities. If
you wish to use GeoConvert directly,
<a href="https://sourceforge.net/projects/geographiclib/files/distrib-C++">
download</a>
and compile GeographicLib.
</p>
<hr>
<address>Charles Karney
<a href="mailto:karney@alum.mit.edu"><karney@alum.mit.edu></a>
(2022-04-10)</address>
<a href="https://geographiclib.sourceforge.io">
GeographicLib home
</a>
</body>
</html>
EOF