Deployable multistatic active sonar: the cycle of system design, tests and data analysis

The NATO SACLANT Undersea Research Centre responds to the needs of accurate flexible sonar monitoring in shallow, reverberating environments with a set of small, multistatic sources and receivers to be deployed in a modular, distributed network. This new concept largely relies for its feasibility on the latest advances in digital signal processing, data networks, satellite radio links, underwater communications, accurate geographical positioning, navigation and battery technologies. In turn, deployable multistatic sonars provide the required new features: modular extension of coverage or improvement of detection accuracy, low cost, low risk, expendability, interoperability, flexibility, ease of use and deployment. Since the peculiar characteristics of undersea acoustics highly recommend one to resort to experimental validation, this project is developed through a cyclic sequence of phases: theoretical concept studies-experiments at sea with prototypes-analysis of results -design of a better prototype. The NATO SACLANT Centre is well equipped with the necessary resources to conduct this kind of mixed theoretical and practical activities. This paper summarizes the experience collected with the first prototype system and during the definition of a new technical demonstrator. It reports the outcomes of several campaigns and data analysis processes. The advantages of having multiple views of the target and of extending the coverage with covert receivers are shown. The process of validation, analysis and extrapolation of results by means of propagation modeling is also described