Signal Processing and System Concepts to Exploit Passive Signals in Airborne Active ASW Missions

Future Airborne ASW tactics will depend heavily upon the use of active sonar and bistatics with a distributed field of sonobuoys as the primary means of initial target detection and localization. However, the bistatic detection and classification problem is compounded by short contact times, evasive target maneuvers, and the ambiguous nature of target echoes and clutter. Recent studies indicate that some target signals are potentially exploitable by passive detection, even in the acoustic and tactical environments of interest for active search. A method of detecting these signals, and a method of incorporating the clues provided by such detections, is desired to augment the information obtained from the processing of the active sonar data. A system level approach to achieving this passive signal detection, and implementing the techniques in an Air ASW active search mission is proposed.The proposed techniques will demonstrate that the passive detection methods are useful, and that they provide added value to current and future active search based Air ASW missions.