Browsing Reprints by Subject "Acoustic scattering"
Now showing items 1-14 of 14
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A novel approach for a bistatic scattering calculation suitable for sonar performance model
(CMRE, 2014/01)One of the classical approaches to the calculation of the sound pressure scattered from a rough surface is to sum the contributions to the field from a set of small tiles that approximate the surface. If the tiles are ... -
Acoustic scattering from rough surfaces
(NATO. SACLANTCEN, 1975/10)A review of scattering from the ocean bottom and ocean ice cover is given. Areas of deficiency are cited. -
Acoustic signal dispersion and distortion by shallow undersea transmission channels
(NATO. SACLANTCEN, 1997)The undersea littoral is an adverse medium for acoustic signal transmission to horizontal ranges of many water depths. Reflections and scattering in the bounded, nonhomogeneous channel disperse the arrivaj of received ... -
At-sea measurements of acoustic elastic scattering by a 1.5m-long cylinder made of composite materials
(NURC, 2007/12)Monostatic and bistatic acoustic scattering measurements were performed on solid-filled fibreglass objects (a sphere and a cylinder with hemispherical endcaps) deployed proud on a sandy seabed and insonified by a rail-mounted ... -
Beam spreading and loss of spatial coherence in an inhomogeneous and fluctuating ocean
(NATO. SACLANTCEN, 1975/10)A theory has been developed that enables estimates to be made of beam bending, beam spreading and loss of spatial coherence. In this paper we concentrate on the loss of spatial coherence due to scattering. Using a minus ... -
Channel-adapted source for shallow water
(NATO. SACLANTCEN, 1993/08)In shallow water areas the utilization of active sonar is complicated by the fact that in these environments the performance of active systems is degraded by source signal interaction with channel boundaries. These boundary ... -
Evaluation of low-frequency bottom backscattering strength vs grazing angle by means of multiple beamforming
(NATO. SACLANTCEN, 1986/06)Bottom backscattering strength was measured in deep water as a function of grazing angle in the Balearic Abyssal Plain of the Mediterranean. The measurements were made with a towed, narrowband low-frequency omnidirectional ... -
High frequency acoustic observations of Mediterranean flow into the Black Sea
(NATO. SACLANTCEN, 1997)The physical behavior of Mediterranean flow entering the Black Sea through the Strat of Istanbul is described using a variety of high frequency acoustic systems. Because of the density difference between salty Meditermnean ... -
Scattering from a random interface
(NATO. SACLANTCEN, 1975/10)The problem of scattering from a random interface separating two fluids with different densities and sound speeds is considered. The method is to write coupled integral equations in coordinate space connecting the surface ... -
Separability of scattering and reflection parameters in reverberation inversion
(NURC, 2007/11)A premise of reverberation inversion is that one can separate geoacoustic reflection properties from scattering properties since their effects on reverberation are distinguishable. Some doubt has been cast on this premise ... -
Separability of seabed reflection and scattering properties in reverberation inversion
(NURC, 2007/02)Separation of scattering properties (Lambert's mu) from reflection properties (the reflection loss angle derivative alpha) presents difficulties in the geoacoustic inversion of long range reverberation in isovelocity ... -
Some acoustic effects of internal macrostructure
(NATO. SACLANTCEN, 1975/10)Some recent experimental developments relating to internal oceanographic- acoustic interactions are reviewed. Besides amplitude and phase fluctuations, a major concern is scattering into shadow regions. Associated oceanographic ... -
Tank measurements of elastic scattering by a resin-filled fiberglass spherical shell
(NURC, 2007/12)Acoustic elastic scattering measurements were conducted in a tank on a 6cm radius fibreglass spherical shell filled with a low-shear-speed epoxy resin. Preliminary measurements were conducted also on the void shell before ... -
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 ...
