Hmm. A group of us at our local hackerspace is building an autonomous robot. We already have that 9DoF sensor as well as a GPS and barometer. I'm able to accu

Hmm. A group of us at our local hackerspace is building an autonomous robot. We already have that 9DoF sensor as well as a GPS and barometer. I'm able to accurately calculate where North(magnetic) is, as well as down, and roughly what altitude I am, and synchronize them to sporadic GPS locks. Depending how useful, this could be good at providing North(true). I'll see if any sort of calibration would be useful (considering I know my lat/lon and can calculate the expected rotational vector). I'm investigating using ORB-SLAM with ROS to also provide accurate locations of the localization. The whole idea is that I can use this as yet another piece in a probability-location detection as well as map other things quickly and accurately.