Scattering from sub-critically insonified buried elastic shells

Buried mines have been so far generally considered undetectable by conventional high frequency sonars mostly due to the low levels of energy penetrating into the sediment at high frequencies. Furthermore, in a shallow water environment a high frequency high grazing angle mine-hunting sonar approach is vastly limited by the coverage rate, making the detection and classification of buried objects using subcritical grazing incidence an attractive alternative. In mine countermeasurements (MCM) applications resonance of man-made elastic targets is a pivotal concept that distinguishes them from rocks or other clutter that may have a similar mine-like shape. Nevertheless, burial of an elastic target in the seabed results in a variety of modifications to the scattered response caused by different physical mechanisms, geometric constrains, and intrinsic properties of the sediment. The goal of this thesis was to identify, analyze and explain the fundamental effects of the outer sediment and the proximity of the seabed interface on the scattering of sound from elastic shells insonified using low frequencies at subcritical incident angles.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Ocean Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Lucifredi, Irena

Advisor dc:contributor.advisor

• Henrik Schmidt.

• Ocean Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/33451

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33451