Measuring and Modeling the Temporal Coherence of High-Frequency Seafloor Scatter
Abstract
"Approved for Public Release"Our overall objective is to advance understanding of the temporal coherence of acoustic scattering from the seafloor and the factors whichimpact it. Results may lead to advanced remote sensing of seafloor processes important to predicting the performance of current or future naval sonar systems. To meet our objectives for this work we will collect and analyze time series of acoustic scattering collected in several Gulf of Maine locations to estimate coherence, its influencing factors, and the variability in coherence over long time scales. Other objectives of the project are to tie measurements to local environmental parameters and to use this information to develop quantitative predictive models. These objectives are based on the sensitivity of the scattered acoustic field to changes in the orientation of seafloor scatterers. It is not an understatement to saythat the proposed novel acoustic measurements provided by coherence would yield a level of detail on seafloor dynamics which would be a huge addition to our acoustic seafloor measurement toolkit.Our proposed work aims to obtain at-sea experimental measurements of coherence in water depths of 50 # 300 meters in various locations in the Gulf of Maine, which are planned to overlap current instrumented lander locations of the University of New Hampshire#s Atlantic Environmental Observation Network (AEON) locations. These measurements will give insight into the coherence of acousticscattering as it relates to local physical the biological variations of the seafloor at the measurement sites over timescales from hours up to a year. This study will focus on collecting and analyzing data acquired from moored transducers covering a wide range offrequencies connected to an autonomous acquisition system. To perform a comprehensive investigation, environmental measurements will also be acquired concurrently, and will include water column properties collected via CTD, current measurements collected via ADCP, and seafloor roughness measurements collected via stereo photos. Measurements will be collected over much of the three-year timeframe of the proposed project. Environmental measurements will be used to identify major factors influencing coherence and its long-term variability. As part of our effort, we will also begin the development of predictive models of coherence which use local sedimentproperties, animal types and abundance and measured environmental parameters. Suggestions will also be made for future studies based on knowledge gained in the proposed study.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 24, 2023
- Source ID
- N000142312747
Entities
People
- Anthony P. Lyons
Organizations
- Office of Naval Research
- United States Navy
- University System of New Hampshire