Source development for a seismo-acoustic sonar
By: Sean M. Fitzpatrick
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 98
Description: Buried mines in the beach and surf zone hinder Naval power projection beach assault operations and endanger humans. In this research, it is demonstrated that seismic interface waves on the surface of a natural beach can be used to detect buried, mine-like objects. A seismic sonar system, employing guided interface waves known as Rayleigh or Scholte waves has been proposed for detecting shallow, buried ordnance and is the subject of an ongoing, ONR- sponsored research program at the Naval Postgraduate School. The primary purpose of this research was to develop an improved seismic source to evaluate further the concept of using a seismo-acoustic sonar to detect buried ordnance in the beach and surf zone. The developed source was based upon a linear magnetic force actuator. Additionally, testing procedures were developed for follow-on research. Seismic interface waves were generated with two, 25-lb force- controlled linear actuators operated as shakers. The waves were measured with a two-element horizontal array of three axis seismometers. Buried, mine-like objects, ranging from 71kg to 290kg, and at ranges of up to 5 meters were echo- located by visual examination of the raw, recorded seismic signal, and by the use of polarization filtering signal processing.
Notes: "December 1998."

Thesis advisor(s): Thomas G. Muir, Steven R. Baker, Anthony J. Healey.

Thesis (M.S. in Applied Physics, M.S. in Mechanical Engineering) Naval Postgraduate School, December 1998.

Includes bibliographical references (p. 95-96).

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System Requirements: Adobe Acrobat reader.

US Navy (USN) author.

dk/dk cc:9116 02/19/99.