Saturday, February 23, 2013

Junior Iditarod tracker is live and free

Not to be confused with "wild and free."

Anyway, the Junior Iditarod teams are on the trail, and like last year the Iditarod is providing free live tracking.  This year IonEarth has added an analytics page, so I've been taking a quick look at it to try to figure out whether or not it's helpful, what I can learn from it, what I can't learn from it, and so on.

The thing I ran into when looking at the Iron Dog tracker is that I had no idea what they meant by their various averages.  It looked like "moving average" and "average" were possibly the same thing, with one taken over more terms.  It turns out that while the definitions are not available on the Iron Dog tracker, they are available on the Jr Iditarod page, and look like this:

So, this was something of a surprise (as in a big one), since "moving average" means something to statisticians, and it's not this.  Both their average speed and moving average speed are actually cumulative averages (probably?  they aren't very clear).  Also, my suspicion is that "Speed" is not "across the course," but is actually instantaneous speed.  Anyway, I think they could remove the confusion and be much clearer (to both of us mushing fans with statistics backgrounds ... ) by changing "Moving average speed" to "Average moving speed."

After looking at the Iron Dog tracker and thinking that I had a pretty good handle on what was actually on the analytics plots (and being largely wrong ... ), this morning I looked at the Jr Iditarod analytics and immediately sat down to try to figure out what the curves represent:


[Also, go Noah!  Upstate NY represents!!].  So I was eyeballing the red line and trying to figure out if it was being taken over more terms (which seemed likely) than the purple line, and then I looked at the legend.  And, d'oh!  it's actually the temperature curve.  If they're going to put that on the plot at all they really need to put it on the same plot as altitude (the upper blue line), since it represents environmental factors and is just really confusing on the speed plot.  So, moving it up would make the plot a lot clearer.

I was also having some difficulty understanding how the curves can be so smooth given the very, very small number of samples (the race started at 10am AKST, it's now 11:30am AKST).  I think they just drew some B├ęzier curves, decided they look nice, and left it at that (Chris says "It looks like the analytics are a response to an RFP") rather than worrying about what information was being conveyed.

But, it's very, very early in the race and at this point I'm not sure how much useful analysis can be done, anyway.  As the race progresses I'll be very interested in how the speed curves represent what's happening in the race.

IonEarth makes incredible hardware - there's absolutely no question about that.  That they're as reliable as they are makes it possible to learn a lot more by glancing at their tracking map than you can by just looking at positions on a Trackleaders tracking map (because the SPOTs are less reliable you also need to take a look at the age of a "breadcrumb").  I'd love to see them improve their analytics, even though I'll acknowledge that it's probably just a small minority of us interested in those things.  What they've got now is pretty but perfunctory.

1 comment:

  1. I'm no techie but I enjoy the analytics page(s) for both IronEarth and Trackleaders.

    The trick is, as Melinda has pointed out, learning to correctly and fully interprete the displays.

    Melinda's blog and just diving into it should bring me a better understanding over time.

    Thanks Melinda!

    ps//It looks to me like the IronEarth Analytics page dosen't auto-update. As for the misplaced Temperature Curve- I got rid of (deleted) that thing pronto!

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