Acoustic Signature Monitoring and Management of Naval Platforms

Acoustic signatures make naval platforms susceptible to detection by threat sensors. The variable operational conditions and lifespan of a platform cause variations in the acoustic signature. To deal with these variations, a real time signature monitoring capability is being developed, with advisory tools for signature management. Such a functionality creates awareness of the own acoustic signature and possibilities for interventions. This paper deals with a modular approach which is being developed for real time acoustic signature monitoring and management. This approach is based on monitoring the acoustic signature of a platform by measuring on-board acoustic accelerations at specific locations. Within an acoustic condition monitoring module the acceleration data are processed and deviations in the sensor data are detected. A diagnostic module tries to determine the cause for these deviations. An estimation module uses previously calibrated correlation factors between on-board acceleration signals and underwater sound measurements to estimate the acoustic source level signature. Furthermore, a prediction module generates predictions of the acoustic source levels for alternative platform settings, which serve as input for the advisory tool. The architecture of this approach, which will be applied in a demonstration of an integrated ship signature management system, including also other ship signatures, is explained in more detail. The approach and current developments are illustrated by practical examples based on the experience obtained from trials with research vessels on an acoustic range.