Littoral Geoacoustic Surveys Using an Adaptive Network of Gliders

Acoustic sensor systems are the backbone of both anti-submarine (ASW) and mine-countermeasure (MCM) systems. Inadequate knowledge of the acoustic environment, especially in denied areas, results from a lack of survey equipment, funding, and access to areas of tactical interest. Moreover, the acoustic environment can change substantially depending on conditions such as sound speed, water depth, and surface conditions. Predictability of specific acoustic conditions has proven difficult. Only the roughest estimates, by definition incorrect, are available to today's warfighter. The ability to measure the acoustic environment directly is essential. Of the many measurements possible the most useful to the warfighter are the sound velocity profile, bottom loss, and bottom reverberation. This proposal will design a system for determining bottom loss and bottom reverberation characteristics with an active acoustic source and distributed receivers. The proposed system will be suitable for deployment on autonomous underwater gliders, allowing investigation of denied areas. Multiple gliders may be driven by a detected "source" to adaptively move and reconfigure to achieve array gain as required.