Air ASW Full Field Scattering

The US Navy uses multistatic acoustic sensor systems with Air Anti-Submarine Warfare (ASW) aircraft, supporting acoustic sources and receivers in a coordinated ASW search and surveillance mission against conventionally powered submarines operating inshallow water as well as all submarines operating in deep water. Current systems suffer from high false alarm rates when operating in shallow water.The opportunity exists for optimally exploiting the full scattering field of the target's response to multistatic sources. Exploiting this full field scattering approach should improve sonar performance. Fusing together multiple echoes originating from thesame target has the potential to reduce false alarm rates for the sonar system.There are several difficulties in using full scattering field detections. One difficulty is that target motion effects may be required to eliminate some classes of clutter. Another difficulty is that target aspect information is needed to optimally combinemultiple echoes.Signal Systems will use an optimal likelihood ratio tracker as a framework for exploiting the full scattering field effects available in Air ASW multistatic systems. This tracker will incorporate Metron Inc's Bayesian target tracking technology. In PhaseI, we will develop a preliminary full field scattering detection method and evaluate its performance using at-sea data sets. This research, if sucessful, will increase search rates and reduce false alarms in Navy multistatic sonar systems, such as Extended Echo Ranging (EER), Improved EER (IEER)and Distant Thunder.