Part I - Undersea Warfare Systems Briefing Paper
During the long period when undersea warfare was characterised by a blue water orientation, the traditional hull-mounted active/passive sonar was joined by the passive towed array (offering a longer range with fewer interference problems). As undersea warfare moves into green and brown water, active transducer elements are being added in order to create an active/passive towed array. New signals processing technology is allowing the use of lower frequencies in shallow or obstructed water, thus increasing the range of active sonars in these environments. Using these systems successfully is a major challenge.