Re: It's not a compass.
The original concept was (is) called SINS: Ship's Inertial Navigation System
accelerometers sense movement along all 3 axes and track displacement
It is not Dead Reckoning, but a technological replacement. From over 50 years ago.
The main difference between SINS's gyroscopes and quantum "compass" is sensitivity (and need for extreme cooling).
Biting the hand that feeds IT
