MRI: Development of a Lightweight Towed Array Receiver (LTAR) for Wide Area Ocean Monitoring and Imaging

Northeastern University, Boston MA

Investigators

Abstract

The PI requests MRI funding to develop a Lightweight Towed Array Receiver (LTAR) system for rapid, wide area monitoring, and measurement of the ocean environment with acoustics. The LTAR will serve as a general purpose mobile ocean remote sensing tool to study marine life, oceanography, geologic and geophysical properties of the ocean environment, anthropogenic noise in the ocean and its effect on marine life. It will enable fundamental new scientific advances in each of these areas. The LTAR will be designed to receive signals from the sub-audible range (tens of Hertz) to above the audible (tens of kiloHertz). For passive sensing, it will be possible to sense signals over trans-oceanic scales, while for active sensing such as with OAWRS (Ocean Acoustic Waveguide Remote Sensing), it will be possible to instantaneously image areas in excess of 100 km diameter. The LTAR system will be comprised of a line array of passive underwater acoustic hydrophones coherently synchronized for high resolution directional sensing over wide areas and a handling system designed for towed deployment from a generic surface research vessel. The LTAR system design will be portable, user-friendly, economical, efficient and optimized for high performance, wide-area monitoring and surveying of the ocean environment. System compactness will enable joint tow with complementary equipment, such as source arrays, even on smaller research vessels, significantly reducing the cost of at sea research and opening up usage to a much broader range of researchers. The LTAR will be light enough to also deploy from unmanned or autonomous underwater vehicles. It will be deployable in both horizontal and vertical configurations. Broader Impacts: The proposed towed array with such high precision coupled with the concept of multiple users will significantly increase researcher?s ability to do precise measurements across many scientific disciplines in the marine environment. It will be a valuable resource that will play a major role in improving the state of science in ocean research over a wide range of scientific discipline and allow the USA to maintain its eminent role in ocean science. If the system can be mobilized cheaply and spend significant amounts of time at sea it is realistically possible to keep enormous areas of the continental margins under continuous observation. The potential consequences for our understanding of fisheries biology are amazing, especially integrated with the satellite monitoring of ocean color, sea surface temperature and fishing boat activity. Many of the proposed research activities that would use LTAR would be multi-disciplinary and likely involve undergraduate, graduate, and postdoctoral students. LTAR team members from academia actively mentor students, including women and underrepresented groups, in their research efforts, and this would be expected to continue or expand with LTAR-related research projects.