Acoustic Intensity Localization System

Applied Physical Sciences Corp. (APS) proposes the Phase II development of an Acoustic Intensity Localization System (AILS). AILS utilizes a vector hydrophone to measure the latitude-longitude offset to an acoustic projector attached to surface buoy whose position is known via GPS. A major advantage of the AILS concept is that it can operate with extreme precision even at relatively low frequencies (e.g., < 5 kHz) without requiring extensive array aperture. As a first application, APS will design a prototype AILS for integration with the Surf Zone Crawler Vehicle. The prototype AILS system electronics will be integrated with the Woods Hole Oceanographic Institute's acoustic Micro-Modem. In Phase I, APS demonstrated feasibility of successfully implementing the AILS in the Crawler application. In Phase II APS will execute a first article fabrication and calibration, and extensively test and evaluate the end-to-end prototype. Key environmental influences, such as refraction and surface wave motion, will be a major focus of full prototype system tests. Additionally, APS will leverage development of the localization system to investigate alternate uses of the components and features of the AILS, such as enabling a sea-based differential GPS base station and using the source/receiver arrangement as a bistatic, active sonar for obstacle avoidance.