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Relative contribution of surface roughness and bottom attenuation to propagation loss in shallow water
(NATO. SACLANTCEN, 1975/10)
A simulation study has been performed to investigate the relative importance of the contributions of surface roughness and bottom attenuation to propagation loss under differing environmental conditionso The NRL normal ...
Advances in cots side scan sonar for MCM applications
(NATO. SACLANTCEN, 1997)
The Persian Gulf War has elevated the awareness to the problems of shallow water mine detection. Today's high technology shallow water anti-invasion mines, such as the Italian made "MANTA" and the Swedish manufactured ...
Geoacoustic inversion using multipath pulse shape
(NURC, 2008/09)
Experimental data, measured in a shallow water region of the Mediterranean Sea, are used to show that the variation of received intensity with time is well described by existing expressions [Harrison and Nielsen, J. Acoust. ...
Shallow-water coherence of broadband signals
(NATO. SACLANTCEN, 1997)
The frequency-dependent spatial and temporal variabilities of sound propagation in coastal regions is investigated by ezperiment and numerical simulations. Experimental observations show that temporal coherence of the ...
Acoustic propagation models as viewed by the sonar systems designer
(NATO. SACLANTCEN, 1971/12)
The purpose of this paper is to consider the efforts performed in the development of ray acoustic propagation analyses from the viewpoint of advanced sonar system design. In particular, those parameters required of such ...
Critical angle and seabed scattering issues for active-sonar performance predictions in shallow water
(NATO. SACLANTCEN, 1997)
Active sonar performance predictions (0.75 to 3 kHz) are examined in summer shallow-water environments to quantify the impact of variable seabed and watermass properties on detection. Scattering is computed with an ...
Bottom bistatic scattering: experimental results and model comparison for a carbonate sediment
(NATO. SACLANTCEN, 1997)
Bistatic scattering measurements were carried out under the Coastal Benthic Boundary Layer (CBBL) program. The results presented here are for a carbonate sand-silt-clay, and the data were collected in Februar) 1995 near ...
A shallow water system for maximizing echo to reverberation ratio
(NATO. SACLANTCEN, 1993/08)
A method for increasing incident energy on mid-depth targets while at the same range reducing boundary reverberation for shallow water ducts has been devised. The basis of the approach is couched in range dependant normal ...
Sedimentological acoustics: an attempt to reduce the gap between acoustical modeling and sedimentoloogical survey
(NATO. SACLANTCEN, 1997)
A major task in shallow water acoustics is to provide pertinent geoacoustical data. The purpose of the work is to evaluate the state of the art in this field, connecting in situ sedimentological measurement and acoustical ...
Multipath pulse shape in a refracting environment
(NURC, 2007/11)
Multiple boundary interactions in shallow water propagation introduce a more or less Gaussian angle distribution at a distant receiver. When all paths are added the result is 'mode-stripping', i.e. the steep rays are ...