Advanced technologies for undersea surveillance of modern threats

The nature of seaborne threats to coastal states has evolved, with modern threats represented by coastal or mini-submarines, small high-speed attack or infiltration craft, and even jet-skis, and by dramatic increases in the capabilities of conventional submarines fitted with air-independent propulsion. In recognition of these changes, a team of world class companies has joined together to develop sensor, processing, installation and cable protection technology for undersea coastal surveillance systems to meet the challenges of nontraditional targets in littoral waters. The Sea Sentinel Team is comprised of Lockheed Martin Undersea Systems, Raytheon Systems Company, General Dynamics Advanced Technology Systems, and Cable and Wireless Global Marine. The technologies include: innovative installation approaches for littoral undersea sensor systems; improved technology for protection of sensor systems against fishing and other threats; advanced sensor array configurations; rapid and accurate field techniques for array element location; and advanced processing methods for detection, classification and localization of non-traditional targets. An extensive series of in-water demonstrations has shown the effectiveness of this combination of technologies for littoral surveillance. A demonstration array system and processing suite were installed on several occasions in Puget Sound in varying water depths. The array configuration was specifically designed for detection of nontraditional targets in shallow water. The processor used state-of-the-art algorithms to yield substantial detection ranges in the noisy shallow water environment of Puget Sound. This paper addresses some engineering aspects of the Sea Sentinel array system, including impacts on installation and recovery methodologies, and system performance.