Integrated Detection and Tracking in Multistatic Sonar

An ongoing research effort at the NATO Undersea Research Centre (NURC) has included the development of multistatic sonar fusion and tracking technology for effective undersea surveillance. This paper summarizes the progress in this area, and identifies the sensor management tasks that are of current interest. In particular, we study the potential value-added of adaptive data thresholding based on feedback from the current surveillance picture. 1 TARGET TRACKING RESEARCH AT NURC Due to the quiet nature of current threat submarines as well as the complexity of shallow-water acoustic environments, surveillance based on active sonar technology has received considerable attention in recent years. The use of surveillance networks with a number of source-receiver detection nodes provides a powerful framework for effective surveillance, as these provide multiple detection opportunities and robustness against unfavourable source-target-receiver geometries. A number of requirements exist in order to explore the potential of active sonar surveillance networks. The first is the availability of prototype systems to acquire test data. Multistatic sonar surveillance scenarios are generally based on one of two system concepts: mobile platforms (suitable for expeditionary tasks), and fixed/drifting deployed fields (suitable for surveillance of ports, harbors, choke points, etc.). Both system concepts are under evaluation at NURC. A second requirement is the availability of signal and information processing technology that produces manageable sets of contacts for each ping-sourcereceiver triple, contacts that can be exchanged through radio or satellite links for further exploitation at a fusion center. This technology has been demonstrated in NURC sea trials, with both system concepts. A third requirement for undersea surveillance, which is particularly critical in multi-sensor settings with a correspondingly sustained data rate, is the availability of an automated fusion and tracking capability. Typically, active sonar processing will produce hundreds of object-like contacts per ping-source-receiver triple. This may well lead to thousands of contacts per minute in a typical surveillance network. It is critical to extract from this voluminous data a small, manageable number of target-like tracks that are provided to a sonar operator for further analysis. This third requirement has been the focus of an ongoing research effort at NURC that was initiated in early 2002. This effort has leveraged the availability of mobile-platform and deployable-fields datasets and the corresponding contact-level data files (i.e. the first and second requirements noted above). Key milestones in this research have included the following: RTO-MP-SET-095 13 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Coraluppi, S. (2006) Integrated Detection and Tracking in Multistatic Sonar. In Bistatic-Multistatic Radar and Sonar Systems (pp. 13-1 – 13-6). Meeting Proceedings RTO-MP-SET-095, Paper 13. Neuilly-sur-Seine, France: RTO. Available from: http://www.rto.nato.int/abstracts.asp.