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Statistical evaluation of 80 kHz shallow-water seafloor reverberation
(NATO. SACLANTCEN, 1997)
In this work a comparison is presented between 80 kHz reverberation statistics obtained at shallow water sites around Sardinia and Sicily. The data include measurements from several distinct bottom provinces, including ...
A noise directionality model including variable bathymetry
(NATO. SACLANTCEN, 1997)
In this paper we investigate the noise directionality due to distributed surface sources m several envtronments with a uniformly sloping sea bed. Of particular interest are frequency dependence and the question of the ...
Multistatic bottom reverberation in shallow water
(NATO. SACLANTCEN, 1997)
A wavenumber integration approach to modeling of the full multistatic reverberant field produced by small-scale bottom roughness in stratified shallow water waveguides has been developed. A perturbation approach to rough ...
Evaluation of experimental techniques for determining the plane wave reflection coefficient at the sea floor
(NATO. SACLANTCEN, 1986/06)
One of the most commonly used techniques for determinati on of the geoacoustical properties of the sea bed is the measurement of plane wave reflection coefficients at the ocean bottom. An incident field is pr oduced by ...
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 ...
Numerical modeling results for mode propagation in a wedge
(NATO. SACLANTCEN, 1987/11)
A PE (parabolic equation) code is used to study propagation in a shallow water wedge with a penetrable bottom. Particular attention is given to "wedge modes" that have wave fronts that are arcs of circles centered on the ...
A fast field model for three-dimensional wave propagation in stratified environments based on the global matrix method
(NATO. SACLANTCEN, 1986/03)
A three-dimensional fast field program (FFP) model based on the global matrix method will be presented. Compared to traditional propagator matrix methods, the global matrix method allows for a more efficient, and, furthermore, ...
Effects of sea bed structure on high frequency acoustic reverberation in shallow water
(NATO. SACLANTCEN, 1997)
Although undoubtedly sea bed structures, patterns, and composition affect the reverberation of high-frequency acoustic energy, the extent of their influence is not well known. The effects of varying selected bedform ...
Highlights of bottom topography inferred from received depression and bearing angles
(NATO. SACLANTCEN, 1975/10)
Statistical properties of the acoustic reflection from the ocean floor have been studied for a var i.ety of bottom types including deep, smooth, flat topography thorough, jagged bottom in shallower (~l km) depths. Explosive ...
Multipath field representation for seabed parameter extraction using backscatter data from shadow zones
(NATO. SACLANTCEN, 1997)
Inversion strategies for bottom parameter estimation in shallow water impose stringent requirements on accuracy and speed of acoustic models. We highlight the importance of second order effects as first order determinants ...