Countless devices around the world use GPS for wayfinding. It’s possible because atomic clocks, which are known for extremely accurate timekeeping, hold the network of satellites perfectly in sync.
But GPS signals can be jammed or spoofed, potentially disabling navigation systems on commercial and military vehicles alike, Schwindt said.
So instead of relying on satellites, Schwindt said future vehicles might keep track of their own position. They could do that with on-board devices as accurate as atomic clocks, but that measure acceleration and rotation by shining lasers into small clouds of rubidium gas like the one Sandia has contained.
More here. [Thanks to Georg Hofer.]