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Now showing items 21-30 of 41
AUV technology for shallow water MCM reconnaissance
(NURC, 2007/10)
The ability to perform MCM reconnaissance missions in shallow water is important in both expeditionary MCM and in the protection of ports against maritime improvised explosive devices (MIEDs). For many years AUV systems ...
Design of synthetic aperture sonar systems for high-resolution seabed imaging (tutorial slides)
(NURC, 2006/10)
This tutorial reviews the key aspects of the design of synthetic aperture sonar (SAS) systems for
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 ...
Target detection and location with ambient noise
(NURC, 2008/09)
By placing a vertical array in an ambient noise field and forming an upward and a downward beam one obtains two time series which can be cross correlated to reveal a subbottom profile of the seabed [Siderius et al., J. ...
A comparative analysis of side-looking sonars for rapid classification of underwater intruders
(NURC, 2008/09)
One aspect of NURC's 2008 efforts in port protection involves building a prototype system for countering a subsurface threat. Such a capability against underwater intruders in ports requires surveillance of the underwater ...
Network-enabled information fusion in support of underwater research
(NURC, 2007/11)
Advanced communication and information processing techniques can be applied to underwater research to enable new ways of enhancing real-time experimental outcome. This paper is concerned with three main areas where ...
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 ...
Impact of seafloor and water column parameter variations on signal-to-background ratio estimates: a sensitivity study based on sonar performance modeling
(NURC, 2006/08)
Regardless of how accurate modeling can be, if the set of assumptions made with regard to the propagation conditions are not precise, sonar performance predictions diverge from the corresponding measured values. Here a ...
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 ...
Tank measurements of scattering from a resin-filled fibreglass spherical shell with internal flaws
(NURC, 2008/09)
This paper presents results of acoustic inversion and structural health monitoring achieved by means of low to midfrequency elastic scattering analysis of simple, curved objects, insonified in a water tank. Acoustic elastic ...