[Asraelite]

> The first isn’t a good solution for many reasons. Don’t have GPS signal? Shooting next to a magnet? Your system won’t work.

These seem trivial to work around. Just store the last known position and use that. It's rare that you'll be without a GPS signal or beside a magnet, and you certainly won't be traveling long distances in those conditions. And since when do magnets block GPS signals?

[sokoloff]

It’s not that a magnet blocks GPS signals, but it does affect the compass in the context of using 6 of the 9 degrees of freedom in the first proposed solution: “Use the camera’s GPS, accelerometer, and compass to calculate exactly where it is pointed and its latitude. ” (This solution should also do sensor fusion with the gyroscope, not just accelerometer and compass for orientation from a 9DoF system.)