The most useful feature of my new GPS unit is the ability to record and transfer tracklogs. Tracklogs are a GPS-friendly way of making a note of each piece of data they create when reading their latitude, longitude, altitude and time. There are several ways this information can be recorded. Magellan uses a standard non-friendly tracklog format. In this format a line of the track may look like this: “$PMGNTRK,3517.403,N,08115.616,W,00245,M,064603.68,A,,140208*6C”. Not many utilities outside of the Magellan platform will read/use this format. A more “universal” tracklog format is GPX, a format that uses XML to record the information. GPX is a native Garmin format. This format looks a bit like this:
<trkpt lat=”35.290050000″ lon=”-81.260266667″>
      <ele>245.00</ele>
      <time>2008-02-14T06:46:04Z</time>
</trkpt>
This format is very easy to read, but not many devices outside of a Garmin will use it by default. Now, once I get the information converted (currently performed by GeoVisu v.4) I can use the format in any number of applications. Most of the applications I have found DO NOT support using a background map, only a plotting of points… well… I have a TI-83Plus or a TI-89 Titanium that will do that… so we move on to the next step… see what Google can do for me. Google Earth is an application I have avoided for years, because I used to hate it. Google Earth now seems to be ok, so im currently using it to interpret my tracklogs (from GPX format). Another utility I have found that is somewhat useful is called TrailGauge. It uses US Geological Survey and TerraServer data to create a map of the points in the tracklog, but it is very slow and produces maps that aren’t very useful initially, also it is restricted to using about 30km of data at a time… which sucks for longer trips.
I am currently considering training GITI to perform the Magellan TrackLog to GPX Log conversion and perhaps keep a record of all of my tracklogs, but thats a feature for when I have a stronger understanding of the type of data I am working with. I will likely use Google Maps for now for my vehicular trips and TrailGauge for my hiking trips.
There are also some important questions I would love to have answers to:
1. What the hell is GeoCaching?
2. What do sane people do with tracklog data?
3. Are there any good maps availible of state parks that I can use?