Thu, 30 May 2013
GPS Tracking Systems
I use my smartphone in addition to the cyclocomputer in order to be able to record my speed, and later compare the speeds at the same place amongst various conditions. The problem is what to use for tracking and what for reviewing and comparing the recorded tracks?
So far I record the tracks using Move! Bike Computer on my Android phone. It is far from ideal, but at least it stores tracks as a GPX files which are accessible directly from the flash. It uses 1-second intervals, and as a bonus, it can display the track using Google maps. The drawback is that it sometimes does not switch the GPS on, so it needs to be switched on manually from the Android top bar menu. The other drawback is that while it can send the GPX files by e-mail to the desktop computer, it does not remember the prefered export format (GPX instead of KML for me) and the prefered export method (e-mail using K-9 mail to a predefined address). So sending tracks from my phone for further archivation is not so easy. But at least it can be done. Another problem is the start and end of the track: I usually start this app before leaving home, and stop it some minutes or hours after reaching the destination. The recorded tracks then cannot be easily compared, because their durations vary in the order of tens of percent, even though the real time of activity is roughly the same. The auto start/stop feature of the cyclo computer is much more precise - the GPS always report at least some movement because of its imprecision and noise.
As for the viewer, the situation is even worse. So far the best I have found is Endomondo, (and "the best" here does not imply "good" at all). Endomondo can import the tracks in the GPX format, and display them on top of Google map, can generate the speed and height profile, etc. On the other hand, it is way too skewed to training and fitness (computing calories, etc.), and has way too much useless social features. It also has its own proprietary Android App, which makes sending data to Endomondo easier, but with this app it is impossible to get your own data back in an open format. Moreover, when importing GPX data with 1 second granularity, Endomondo rescales it to something more coarse (tens of seconds to even minutes), so it makes comparing the speed at a given place pretty meaningless.
What do you use for your sports tracking, and how does it meet your data accessibility and openness requirements?