Magnetic terrain navigation

The anomalous fieid intensity pattern of the earth´s magnetic field provides a basis for passive underwater terrain navigation. Static magnetic fieids are highly advantageous as information carrying media for underwater applications as they remain uneffected by water and thus easily overcomes the penetration difficulties often associated with underwater navigation systems. Also many underwater structures of interest are themselves strong magnetic anomalies and as such will be natural beacons for a magnetic terrain navigation system and provide excellent opportunities for tracking, position keeping and hovering activities. A new company in Sweden is now developing this concept for untethered submersibles in both civilian and naval applications.