A quantum compass is a compass which measures relative position using clouds of ions.
Description
Developed by the United Kingdom Ministry of Defence for future uses in submarines and aircraft, a prototype quantum compass comprises a one metre long container containing clouds of rubidium atoms frozen using lasers. By measuring the movement of these frozen particles over precise periods of time the motion of the device can be calculated or its proximity to areas of high gravity. It is proposed to use three such containers at right angles to each other to measure change in position from a known location (dead reckoning). The device would then provide a tamper proof accurate position in circumstances where satellites are not available for satellite navigation, e.g. a fully submerged submarine.
Vessels using the quantum compass would need to be equipped with accurate maps of areas of high gravity (e.g. underwater mountains) as these will affect the measurements of acceleration taken on the device.