I looked into quantum inertial navigation a while ago because I wanted to understand - is it some weird quantum thing where they eliminate all accumulated error or not. As far as I could tell the answer is "not" - it's just a very very precise way of measuring acceleration.

Seems kind of hard to imagine that any accelerometer can be so precise you can use dead reckoning to the centimeter over a long time scale. Especially given how strong acceleration due to gravity is.