Underwater Protection System

With the emerging asymmetrical threat to harbours, vessels and areas of special interest the need for both fixed and portable protection systems are imminent. This paper describes a system approach to the problem of protecting vital assets from divers and swimmers all the way from the initial detection through to the choice of reaction including the use of UUV and non-lethal acoustic deterrent units. A vital part of the system described is a novel new sonar system using wideband technology for increased sonar performance in shallow and highly reverberant environments. Further the frequency range has been lowered compared to the standard diver detection sonar of to-day, to give a potential for improved detection ranges and thereby provide more time for carrying out an appropriate reaction. The wideband technology may also lead to a new set of classification tools. The paper outlines the system and specifically discusses tests done in harbours and enclosed environments with the sonar system against divers and UUVs. Detection and classification issues are discussed and examples of obtained system performances are given.