I would theorize that they have GPS in both units, and the tag sends its position to the base. Along with a compass, you can pretty accurately tell where the camera is looking, and you can probably gauge the distance between the tag and camera by the time it takes for the signal to travel to the camera, but I'm not sure how that's useful.

GPS alone isn't really accurate enough by itself, but it's thought that SOLOSHOT integrates both GPS and an inertial system.

According to some of the amazon reviews, it doesn't work within 50 feet. I suspect it does in fact use GPS, as 50 feet would be far enough that you're going to be somewhere in the frame. Couple that with just measuring the delay time, and possibly a compass or something and you'd end up with what they have.

Why not use bluetooth low-energy for this stuff? Or would you need to have three beacons to triangulate?

1) range 2) clock precision (you can't measure time fast enough to actually measure position using bluetooth)

> clock precision (you can't measure time fast enough to actually measure position using bluetooth)

Interesting, why is that and how fast would that be, then?

Also what's different about triangulating via WiFi APs signals, that bluetooth doesn't work?

An educated guess would be that it uses GPS for location. It is often not possible to get a lock on the satellites indoors.

They're working on it however: http://www.extremetech.com/extreme/126843-think-gps-is-cool-...

Is GPS really that accurate, though, that it'll locate you with enough accuracy to allow a camera to center on your position?

If it is indeed using GPS, I'm guessing it's using a GPS in the camera base too, to figure out the correction.

Short-baseline differential GPS with a base station can have cm-level accuracy, if I remember correctly.

That's what I was thinking. Both are viewing the same satellites, since they're close to each other. The base, since it knows it's stationary, can derive the corrections itself, and figure out where the object is.

It's using GPS to figure out where the camera should point.