Ocean Acoustic Reconnaissance Sensor (OARS)

There are a remarkable number of untapped persistent ocean observing assets deployed across the worldÆs oceans that could be used to measure and characterize the acoustic environment on a near-real-time basis. The opportunity exists to use these networks of floats, buoys, and gliders as host platforms for persistent acoustic monitoring to provide not only critical sound environment data for sonar performance prediction, but also for event monitoring that could include alerting on and recording marine mammal vocalizations as well as acoustic intercept signals. The team of In-Depth Engineering Corporation (IEC) and the Applied Research Lab at Pennsylvania State University (ARL/PSU) proposes the Ocean Acoustic Reconnaissance System (OARS) to take advantage of this opportunity. OARS is a compact, low-cost, long-duration, intelligent acoustic sensor system that can be integrated onto a wide range of host platforms, can continuously monitor the acoustic environment, and uses an adaptive signal processing algorithm to analyze the acoustic environment and report details of the ambient sound field to a level of detail commensurate with the host platform communications bandwidth. A key innovation of the OARS solution is the implementation of Cortical Processing ¢ a novel acoustic signal analysis algorithm based on a model of sound interpretation that occurs in the primary auditory cortex of the brain. Cortical Processing will separate the ambient ocean background from marine mammal vocalizations, acoustic intercept signals, surface vessel signatures, and other transient signals. The OARS sensor solution consists of a custom-designed vector sensor constructed from cutting edge textured ceramics that offer higher sensitivity than conventional accelerometers and hydrophones (approaching single crystal capabilities) at a fraction of the cost of single crystal elements, and with a very small physical footprint. Low-power signal processing hardware will operate on a duty cycle to conserve power, only waking up for full signal processing on regular intervals or when an acoustic event is detected.