Eggtimer Rocketry TX Board Rev B4d - Page 16

<?xml version="1.0" encoding="UTF-8"?>
<gpx version="1.1" creator="MapSphere" xmlns="http://www.topografix.com/GPX/1/1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
targetNamespace="http://www.topografix.com/GPX/1/1" elementFormDefault="qualified"
xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">
<trk>
<trkseg>
<trkpt lat="33.822127" lon="-113.138178">
<ele>690.00</ele>
<time>2014-02-22T19:14:43Z</time>
<extensions>
<valid>0</valid>
</extensions>
</trkpt>
<trkpt lat="33.822127" lon="-113.138178">
<ele>690.00</ele>
<time>2014-02-22T19:14:44Z</time>
<extensions>
<valid>0</valid>
</extensions>
</trkpt>
ETC ETC ETC…
The lines that start with “<trkpt” are track points, containing the latitude and longitude of your
rocket’s position. Note that the entry at the beginning of the file will most likely be repeated
many time, since it should be giving you the exact same location of the launchpad for as long
as your rocket is sitting there; since it’s one record per second, you could easily have a few
thousand of the same record, so don’t be alarmed.
Note that these values are in DECIMAL units, not Degree-Minute-Second (DMS) units.
In this case, the first trackpoint is
< trkpt lat="33.822127" lon="-113.138178">
so your rocket’s starting position is 33.822127, -113.138178. This will probably be a little
different from your starting position, since you are going to be standing some distance away
from the rocket.
Now, go to the end of the file, and look for the last <trkpt…> record. The latitude figure is the
one that starts with “lat=”, and the longitude value starts with “lon=”.
<trkpt lat="33.828873" lon="-113.130500">
<ele>683.70</ele>
<time>2014-02-22T19:17:59Z</time>
</trkpt>
</trkseg>
</trk>
</gpx>