Three Dimensional Acoustic Effects in the Middle Atlantic Bight.

• Main Author: D'Agostino, Anthony F.
• Other Authors: NAVAL POSTGRADUATE SCHOOL MONTEREY CA
• Format: Text
• Language: English
• Published: 1996
• Subjects: Acoustics; *SOUND TRANSMISSION; *UNDERWATER ACOUSTICS; FIELD TESTS; THESES; THREE DIMENSIONAL; CONTINENTAL SHELVES; BATHYMETRY; CONTINENTAL SLOPES; ACOUSTIC MEASUREMENT; TOMOGRAPHY; ACOUSTIC VELOCITY; NORTH ATLANTIC OCEAN; ACOUSTIC FIELDS; ACOUSTIC REFRACTION; *ACOUSTIC TOMOGRAPHY; MIDDLE ATLANTIC BIGHT; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADA314805; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA314805

Under the sponsorship of the Office of Naval Research (ONR) PRIMER program, an integrated acoustic and oceanographic field experiment will be conducted jointly by the Naval Postgraduate School (NPS) and the Woods Hole Oceanographic Institution (WHOl) in the Middle Atlantic Bight (MAB) to study the propagation of sound from the continental slope to the continental shelf. In support of this field study the three-dimensional (3D) effects of the basic mean shelfbreak frontal thermal structure and sloping bathymetry on the planned tomography signal transmissions are modeled using ray methods. Both three-dimensional (3D) and two-dimensional (2D) ray paths and signal arrival structures for an upslope and cross-slope source-receiver geometry are simulated and compared. While the input sound speed field is from a previous summer-time hydrographic section, the input bathymetry is from a recently declassified U.S. Navy DBDB-0.5 data set. Significant 3D environmental effects are found in the modeled cross-slope transmissions, indicating that the physics of horizontal refraction and out-of-the-vertical-plane scattering will be required to properly analyze the acoustic measurements and to construct accurate tomographic maps.