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Measurements and modelling of high-frequency acoustic scattering by a rough seafloor and sea surface
(NURC, 2009/12)
Acoustic scattering by a rough, possibly dynamic interface is experimentally studied by insonifying the seabed and the sea surface at high frequency at various incidentangles. A directional source working at 300 kHz was ...
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 ...
Determination of velocity profile and sea bed characteristics from high frequency pulse propagation in a shallow water Mediterranean environment
(NATO. SACLANTCEN, 1997)
Time-domain features of shallow water Mediterranean and Yellow Sea data are simulated for frequency band widths of 0.8 kHz with a centralfrequency of 3.2 kHz. Contour plots of pulse arrivals in time and depth are analyzed ...
The effect of suspended particulate matter on the performance of high frequency sonars in turbid coastal waters
(NATO. SACLANTCEN, 1997)
Shallow coastal environments are characterised by high levels of suspended mineral particles relative lo the open ocean and such suspensions can have a significant effect on the performance of high frequency sonars operating ...
Modeling range-dependent, high-frequency, shallow-water torpedo reverberation data
(NATO. SACLANTCEN, 1997)
The high-frequency, forward bottom losses predicted by a lossy Rayleigh and a Biot poroelastic sediment model are substantially different. These differences will accumulate and become measurable in multiple bottom bounce ...
High frequency matched field processing
(NATO. SACLANTCEN, 1997)
Results are discussed from a high frequency (0 9-5 7 kHz), very shallow water (<10 m) experiment exploring the feasibility of carrying out matched field processing in this frequency and water depth regime The data was ...
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 ...
Uniqueness problems in extracting environmental parameters from high-frequency shallow-water reverberation measurements
(NATO. SACLANTCEN, 1997)
Inversion techniques that extract environmental parameters from measured reverberation often lead to mathematical problems that are not well-posed. Two examples illustrate this possibility. The first hows how a model can ...
Analysis and problems of HF acoustic coherent and incoherent simulations in shallow water
(NATO. SACLANTCEN, 1997)
Shallow water environments create complex scattering condit~ons due to the sea surface and bottom scattering mechanisms. An analysis of the effects of the scattering mechan~smso n sonar images of simple targets in shallow ...
Very-high (cm scale) resolution multichannel seismology
(NATO. SACLANTCEN, 1997)