◌  GPS data ideas

27 January 2009

I have about 650,000 points of GPS data over about 13 months. Each is a time, latitude, longitude, elevation, and velocity. Elevation is iffy because of course GPS isn’t so hot at it; off the top of my head, I’d say its standard deviation is about 5 meters under clear sky and 25 in forest. Velocity is iffy because I messed with the firmware to make it stop dropping stationary points and switch from km/h to m/s, but like an idiot I didn’t mark exactly when, and the fix will have to be eyeballed. So we’re not looking at science-quality data, but it’s good enough to be very interesting.

What should I do with it?

I’ve been having fun looking at velocity over elevation, elevation over time, lat/lon over time, and so on. I’ll show some later.

Michael Orth, websiteless freak, suggests using elevation and velocity to work out my potential and kinetic energies over time. This could go a step further to figure out how many calories I burn. (Let’s assume it’s easy to distinguish foot motion from that of bikes, cars, trains, and boats.)

Eventually I’ll take the points, find some algorithms with Delaunay in their names, and make a mesh modeling elevation everywhere I’ve been. (And one of these days I’ll leave the tracker on the high point of the island overnight. Surveys have listed it as both 580 and 612 feet. My best readings so far suggest about 183 m = just about 600 feet.)

So what would you do with this data? Send your idea today.