Since June 2005, I’ve been collecting tracklog data using my Garmin GPS 60 (CSx). This means that every time I go cycle racing, walking, sailing, ice skating or even flying, I bring my Garmin, turn it on and (automatically) log the track.
After the track is completed for that activity, I archive it at home, as a GPX file, using Garmin’s MapSource.
I initially bought the GPS for tracklogging and navigational purposes for my bike trip from Arnhem (Netherlands) to Paris, but keeping all tracklogs did give me some other cool opportunity that I didn’t think of back then.
One example of that is gathering statistics about my cycleracing and mountainbiking trips, thereby motivating me to break new records and discover new terrain. Another cool purpose for all my tracklogs, and what this blog is about, is that I can visualize them (all at once) on Google Earth!
With Google Earth and converting tools like GPSBabel at our disposal, it’s possible to create a (big) Google Earth file of all tracklogs combined. When I try to combine, for example, the activities for which I have the most tracklogs available (cycle racing, mountainbiking, walking, cycling on my hybrid bike and sailing), I assign them a color so I can differentiate between different types of activities and create really cool and insightful maps, like this:
In this picture, the red colored line stands for mountainbiking, purple stands for cycling with my hybrid bike, blue is used for cycle racing and green is for walking. If you look carefully, you can also guess where I must live somewhere 
This map might look not very organized or useful to other people, but for me, there are many, many stories and new ideas hidden in it.
There are a lot of interesting views possible, seen my pretty large collection of tracklogs. This one for example is from my holiday last September in and around Cassis (south France):
The pink line show a sailing trip we’ve taken. The green line shows the walk we took to Calanque d’En-vau and the blue line shows a cycle racing trip over the Route du Crête. If you ever want to visit this area, it’s a good thing idea to take my tracklogs, put them on your GPS and do the activities while you are in the area, so you don’t miss the ‘must-have-done’s’.
This whole thing looks somewhat like everytrail.com, where one can create some sort of “trackblog”, including photo’s that can be linked to the track. But an overview, loadable in Google Earth is not one of the options they offer (yet). But maybe they add it in the future, so, if you start uploading your tracks at everytrail.com now, an easy total view in Google Earth might not be so far away at all
Luckily you can create such a combined track yourself as well, however it requires some scripting knowledge. To combine the (GPX) files you can use gpsbabel, remove all but the track-information from the tracklog, for each of the tracklogs from a certain category, and output them to a kml or kmz file, a command that looks like this on unix:
/usr/local/bin/gpsbabel -i gpx -f "Tracklogs Varen/20080611_Drangey_Sauðárkrókur.gpx" -x nuketypes,waypoints,routes -i gpx -f "Tracklogs Varen/20080611_Sauðárkrókur_Drangey.gpx" -x nuketypes,waypoints,routes -i gpx -f "Tracklogs Varen/20080824_RoelofarendsveenLeiden.gpx" -x nuketypes,waypoints,routes -i gpx -f "Tracklogs Varen/20080908_CalanqueDePortMiou.gpx" -x nuketypes,waypoints,routes -o kml,floating=0,labels=1,trackdata=1,line_color=FF00FF00,points=0,line_width=2 -F "combined_varen.kml"
After that I load each kml file in Google Earth separately and assign it a unique color. By moving the track to the same folder in Google Earth, I can combine them to one track, with multiple colors per category. That’s all it takes.
The most actual version of all my tracks in the categories cycleracing, ‘Cycleracing with hybrid bike’, sailing, mountainbiking, walking, ice skating and flying can be found in this automatically updated Kml file.
Some more screenshots that I’ve taken are available here: http://public.hendricksen.eu/GpsArt/
I hope I can inspire people to do the same, or at least motivate them to start collecting and archiving their own tracklogs, so at some point, they can create some cool maps just like I did with my tracklogs, and who knows, maybe start comparing those tracks.
Update 2009-12-03:
The latest combined tracks file (automatically updated) with all my cycling, walking, sailing and skating tracklogs are available here.
excellent post jeroen. i have tried to duplicate your experiment with my mountainbiking tracks in waterdown, ontario, canada. i’m having some success, but am hung up on trying to combine the tracks in google earth. i can’t seem to get the tracks to all be visible at once. any tips on this specific part of the process? the google earth documentation is proving a little thin in this regard.
thanks,
doug van es
Hi Douglas,
I have run into the same problem with the latest Google Earth. I had loaded the tracks, assigned it a color and thickened the line to ’3′, but nothing was visible. I found out there where two caveats in the process of creating the overall KML file:
-There is a timeline in Google Earth. By default it doesn’t select all the tracks. You should slide this timeline so all of the available time from start to end is covered. By default it shows only the first track on the earliest date.
-Every track you’ve opened/imported has altitude markers. In Google Earth you can define how they influence the visibility of the track on the map, especially relevant in 3D view. Go edit the folder containing the tracks, go to the tab ‘Hight’ and choose something like ‘clamped to the ground’. this should make the track always visible, even with big differences in height. It can also help to switch the ‘Terrain’ layer.
Please let me know if this helped to solve your problem. If you have any further questions please ask them, I’d love to help you get this working!
Jeroen
the timeline trick was the key to getting my multiple tracks to show up. thanks jeroen!
Hi Jeroen,
I’m searching for ways to use Google earth and KML’s created miles apart but around the same course. Then bringing the KML’s to the same start point and running them together so we can have a virtual UAV race!!
The racing has begun http://diydrones.com/profiles/blogs/announcing-the-official-diy
Now it would be nice at the end of the month to bring an animation together of everybody racing all around the world as if we were together!!
Im not clever enough to work out how to do it!!
Cheers
G
Hi Gary,
Sorry for my late answer.
I think I understand what you want to accomplish. I’m sure it’s possible, but it requires additional help from tools like GPSbabel and a tool you have to make yourself.
What you need to do with every race-track is shift the trackpoints times all to the same point in time, so that the first trackpoint (where the race starts) is set to the same time point. This is possible with the “Move” action from the gpsbabel tool. You’ll have to calculate the difference yourself for each track, but it can work.
Another thing you have to do – and this is the hardest one – is shift all the location data for each single race in a way so that the starting point of each track points to the same location. I don’t know any tool that can do that, but you could apply some very simple addition and subtraction to each of the coordinates that are part of the track, it might give you a reasonable result, though this might also result in strange results if the track was recorded at a location on earth that is relatively far away from the point you want to shift it to.
So i think it can be done, but it requires some experimenting and the need for writing a little tool that can ‘shift location data’.
Kind regards,
Jeroen