Feb 27, 2015 | GPS tracking my ski trip in Vail

This past week I had the chance to ski in Vail, Colorado, and I took with me my BadElf GPS Pro as I skied up and down, into the Back Bowls and the Blue Basin. I’m always interested in recording all sorts of odd bits of data, so I figured my ski tracks would be fairly revealing.

BadElf tracks GPS points every second and, once done, generates KML files that can be exported relatively easily. But rather than purely visualize where I went, I wanted to see elevation and speed differences as well. So I threw the data into Google Earth and ran the time slider animation.

The visualization is nice and all, but I wanted some real numbers, so I stripped down the KML files (for some reason BadElf’s exports contain duplicate information) and concatenated them into the two days (Saturday and Sunday) that I skied. Day 2 follows Day 1.


On both days the peak speed is around 40km/h, though there are instances where I appear to cross the 60km threshold. It’s important to ignore the first couple of kilometers as it’s likely I’m on the shuttle bus from East Vail to the gondolas; also, on the second day, some GPS triangulation errors seem to introduce erroneous GPS points.


I was fairly surprised at the regularity with which one could observe increases and decreases in elevation. The break at the 30km mark on day 1 is likely lunch. An earlier start to the day on Day 2 means I also got nearly 30km more of skiing.


Finally, this representation was also surprisingly insightful. What you see here is heading — any stretch of similar color and very little oscillation indicates that I was pretty much headed in the same direction. These would likely be instances where I am either on a bus, on a ski lift, or having lunch.

Interested in playing around with the data?

Here are the KML files for Day 1 and Day 2.

This entry was posted on Friday, February 27th, 2015 at 2:35 am, EST under the category of Photography. You can leave a response, or trackback from your own site.