DURIP: 3D Vector Hydrophone Array for Environmental Characterization and Target Tracking
Abstract
This proposal to the DURIP program is for the construction of a 3-Dimensional Vector Hydrophone Array (3DVHA). This system consistsof a tetrahedral hydrophone array as well as a Geospectrum M20-105 vector sensor. The new system will augment URI s existing capabilities by providing the ability to measure in water acoustic pressure and particle motion in 3-D. The availability of the three component particle motion data in addition to pressure will increase our ability to infer the properties of the water column and bottom parameters. The sensing of the vector acoustic field from electronic sources, noise from ships of opportunity, other sources such asSUS and rupture disks in continental shelf environments will allow for more accurate estimates of the water column and seafloor properties including compressional and shear wave speeds and attenuation factors. This vector sensor array will complement our existingbottom mounted sensor system. The existing system consists of six Ocean Bottom Recorders (OBX), and a Geosled consisting of a tetrahedral array of hydrophones. This tetrahedral array of hydrophone data can be used to estimate particle velocities at 1 m above the seabed. The use of vector sensors in the water column has been limited by mooring motion caused by sea surface waves. The new 3DVHAwill utilize a WHOI-designed mooring system with a Stretch Hose. This Stretch Hose dampens the movement of the surface buoy and allows for a high fidelity measurement of the acoustic vector field. With the new capability, we will be able to measure particle velocity on the seabed, close to the seabed (1 m from the seabed) and at mid-water column. The Principal Investigators have been working for a number of years on acoustic sensing of compressional and shear speeds and attenuation in the seafloor of shallow water regionsincluding the New Jersey Shelf, New England Bight, New England Mud Patch area, East China Sea and Barents Sea. The scientific goal of the research using the proposed system is to understand the effects of these sediments properties on low frequency acoustic propagation and thereby improve the understanding of Navy sonar system performance in littoral waters. The frequency dependence of attenuation in the sediment is a subject of intensive investigations from a number of researchers and institutions. One of the key components of the effective attenuation is the conversion of acoustic energy into shear waves at interfaces including the seafloor. This system will allow the estimation of shear speed and attenuation and hence provide valuable information for modeling intrinsic attenuation. Another benefit of the 3DVHA is the capability to localize the sources in azimuth. In addition, the 3DVHA can support the underwater acoustics research community efforts in understanding out-of-plane propagation including diffraction around small islands.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412441
Entities
People
- James M. L. Miller
Organizations
- Office of Naval Research
- United States Navy
- University of Rhode Island