Sensor Technology for Anti-Submarine Warfare

Proposed is an underwater surveillance system for operation in denied littoral areas using autonomous underwater gliders. The approach is particularly suitable for extended surveillance prior to actual conflict and is capable of remote or off-shore deployment of multiple gliders. Gliders, which operate by changing buoyancy and gliding in a vertical saw-tooth profile, bring some unique advantages to this challenging problem: silent operation (no propeller), ability to surface or equilibrate at equilibrium depth, hover as required, long range and extended endurance. An important potential advance is creating a vehicle able to rest on the bottom. Most AUVs must remain in motion, or possibly equilibrium in neutral buoyancy mode at controlled depth with little or no propulsion. The ability to be both mobile and rest on the bottom creates many opportunities. In particular, advantages include: much longer missions; operating during certain hours with quiescent periods; avoidance of bioluminescent trail; remaining quiescent until triggered by events; accurate observation of local tides and currents; etc. A mobile to stationary conversion will allow a traditional bottom mounted sensor platform to be deployed from over the horizon, covertly move into position, and then become a bottom fixture. A design optimized for both mobility and bottom resting is proposed.