An Acoustic Wave and Current Profiler (AWAC) for Mid-Frequency Reverberation Modeling
Abstract
The Autonomous Reverberation Measurement System (ARMS) was developed to make long-term direction-dependent reverberation measurements under all weather conditions. The system consists of a directional acoustic source and receive array mounted on a rotation stage affixed to a benthic lander which can be deployed to collect data autonomously over several days to weeks.The fixed position on the seafloor removes the uncertainties introduced by a moving source making it possible to focus solely on the effect of the environment on the reverberation data. In order to use this data to study the dependence of mid-frequency reverberation on sea surface conditions, it is necessary to measure the sea surface roughness and wave direction at the sametime as the acoustic data is collected. To accomplish this, the ARMS will be complemented by an Acoustic Wave and Current Profiler (AWAC) mounted on a benthic frame. This system can be deployed with the ARMS on the seafloor and collect sea surface roughness and wave direction data while the reverberation data is being collected. Both systems can operate for extended periods of time, without surface expression, capturing data under all weather conditions. The combination of the two systems provides the acoustic and environmental datanecessary to address several key scientific questions: dependence of reverberation levels on sea surface roughness and sea surface wave direction; dependence of reverberation amplitude statistics on sea surface conditions and sonar beam-width; and Doppler spread due to sea surface scattering.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 10, 2018
- Source ID
- N000141812329
Entities
People
- Brian T. Hefner
Organizations
- Office of Naval Research
- United States Navy
- University of Washington