Pose estimate validation / ground truth

Hey folks,

This is a repost -- I first posted it in the Stereo 3D forum, which was probably the wrong place...

I want to start experimenting with mobile device sensors and sensor fusion to estimate pose. This raises the question of how to do validation. Years ago, I tried just double-integrating iOS linear accelerometer data and concluded that my naive approach + the hardware wasn't good enough at that time.

So, coming back to it, how can I rigorously establish ground truth to compare my estimates to? I've seen pictures of a robot arm at Oculus -- but that's a bit out of my price range. Anybody have experience with this?

I'd be willing to start with movement along one axis and/or rotation about one axis only. Maybe I could get by with a custom-machined jig that has a marker at a known distance to some known tolerance?

Thanks in advance for any thoughts and tips!