A preliminary study of shallow-water sonar issues : signal motion loss and reverberation noise
Stewart, W. Kenneth
MetadataShow full item record
This preliminary investigation addresses key program elements for sonar sensing in a shallow-water environment to establish bounds on possible solutions and to reduce program uncertainty. The modeling and experimental program focuses on two issues - the potential degradation of sonar data due to signal masking by shallow-water reverberation and signal loss caused by extreme platform motions. The research program combines theoretical analysis, experimental validation in a shallow-water environment, and development of a computer model to explore parametric sensitivity. Results from an initial dock-side test show good agreement with the theoretical predictions. From the shallow-water experiments and acoustic modeling we conclude that: (1) Signal motion loss can influence the reverberation level significantly but is not the dominant factor in target detection for sonars in the frequency range of interest (>200 kHz); a high-quality (velocity-aided) inertial navigation and attitude system will be sufficient to correct for geometric distortions caused by platform motion. (2) Although surface reverberation and multipath noise can be a factor, partcularly in shadow-mode imaging, reverberation levels are rapidly attenuated at the frequencies of interest and beam patterns can be manipulated to reject most interferences; echo-mode imaging is still dominated by the contrast between target strength and bottom reverberation.
Showing items related by title, author, creator and subject.
A photographic and acoustic transect across two deep-water seafloor mounds, Mississippi Canyon, northern Gulf of Mexico Hart, Patrick E.; Hutchinson, Deborah R.; Gardner, Joan; Carney, Robert S.; Fornari, Daniel J. (Elsevier B.V., 2008-05-21)In the northern Gulf of Mexico, a series of seafloor mounds lie along the floor of the Mississippi Canyon in Atwater Valley lease blocks 13 and 14. The mounds, one of which was drilled by the Chevron Joint Industry Project ...
Morozov, Andrey K.; Preisig, James C.; Papp, Joseph C. (Acoustical Society of America, 2008-09)Acoustical array data from the Shallow Water Acoustics experiment was processed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate ...
Acoustic ducting, reflection, refraction, and dispersion by curved nonlinear internal waves in shallow water Lynch, James F.; Lin, Ying-Tsong; Duda, Timothy F.; Newhall, Arthur E. (IEEE Oceanic Engineering Society, 2010-02-08)Nonlinear internal waves in shallow water have been shown to be effective ducts of acoustic energy, through theory, numerical modeling, and experiment. To date, most work on such ducting has concentrated on rectilinear ...