Reprints: Recent submissions
Now showing items 201-220 of 548
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Antisubmarine warfare applications for autonomous underwater vehicles: the GLINT09 field trial results
(NURC, 2012/05)Surveillance in antisubmarine warfare (ASW) has traditionally been carried out by means of submarines or frigates with towed arrays. These techniques are manpower intensive. Alternative approaches have recently been suggested ... -
The relation between the waveguide invariant, multipath impulse response, and ray cycles
(NURC, 2012/04)The waveguide invariant, b, that manifests itself as interference fringes or "striations" in a plot of frequency vs source-receiver separation, is usually thought of as a modal phenomenon. This paper shows that striations ... -
Target time smearing with short transmmissions and multipath propagation
(NURC, 2012/04)In active sonar the target echo level is often estimated with a propagation model that adds all multipath arrivals. If the (post-correlator) transmitted pulse is short compared to the multipath time spread then there is ... -
Redesigning the SLOCUM glider for torpedo tube launching
(NURC, 2012/04)Launching gliders from a submarine torpedo tube is of special interest for military operations. This is not currently possible because the wing span needed to achieve a good gliding performance is twice the standard diameter ... -
An approximate form of the Rayleigh reflection loss and its phase: application to reverberation calculation
(NURC, 2012/04)A useful approximation to the Rayleigh reflection coefficient for two half-spaces composed of water over sediment is derived. This exhibits dependence on angle that may deviate considerably from linear in the interval ... -
pOctaver, adding scripting language to MOOS
(NURC, 2010/08)NURC uses MOOS-IvP in a scientific research and rapid prototyping environment. Contributions to the open-source suite of MOOS-IvP software is readily made by programmers adept at C++ programming. However, the utility of ... -
On the effects of synthetic-aperture length on SAS seabed segmentation
(NURC, 2009/12)In this work, we quantify the relationship between synthetic-aperture length (or equivalently, along-track resolution) and seabed segmentation performance experimentally for real synthetic aperture sonar (SAS) imagery. The ... -
A contribution to the study of the surface and deep zooplankton in the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)Analysis of 34 hauls of plankton in the Strait of Sicily, from 5 to 21 May 1970, enabled us to make a systematic, quantitative and ecological study of all zooplankton systems present. Vertical fishing was performed with a ... -
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 ... -
Collaborative multistatic ASW using AUVs: demonstrating necessary technologies
(NURC, 2009/12)Many research laboratories and several nations are showing an interest in the 'underwater networked battlespace' in which a combination of stationary and mobile underwater platforms communicate wholly or partially by the ... -
Classification of odontocete buzz clicks using a multi-hypothesis tracker
(NURC, 2009/12)Blainville's beaked whale (Mesoplodon densirostris) buzz clicks have been found to have characteristics that can vary significantly. While we have not succeeded to classify them individually, we find that their spectrum ... -
The intrinsic variability of detection range and its implications
(NURC, 2009/12)The range of first detection of an approaching target is among the most important parameters defining sensors and defensive surveillance systems. A demonstration of capability typically consists of staged approaches of a ... -
Unmanned surface vessels for surface and subsurface threats in harbours: background and practical lessons
(NURC, 2009/12)The use of Unmanned Surface Vehicles (USVs) in harbour protection missions has been studied through technology surveys and experimentation within the programme of work at NURC. The crucial subsystems and vehicle payloads ... -
Detection rate statistics in synthetic aperture sonar images
(NURC, 2009/12)Synthetic aperture sonar (SAS) has proved to be successful for mine hunting andis now robust for generating high-resolution images over wide swath. The subsequent stepin the processing is detection, discriminating between ... -
Multi-view target classification in synthetic aperture sonar imagery
(NURC, 2009/12)This work proposes an elegantly simple solution to the general task of classifying the shape of an object that has been viewed multiple times. Specifically, this problem is addressed in the context of underwater mine ... -
Receiving and transmitting acoustic systems for AUV/gliders
(NURC, 2009/12)NURC in the past years have focused its research on the use of AUV and more recently on gliders and is now developing littoral autonomous sensing networks based onthose sensors to perform missions such as mine warfare, ... -
High resolution sonar (tutorial slides)
(NURC, 2010/07) -
The fauna of the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)All students of the Mediterranean, both biologists and physical oceanologists, now agree t ·hat the Western and the Eastern basins have rather different features and that the Strait of Sicily is there fore an interesting ... -
3D target shape from SAS images based on a deformable mesh
(NURC, 2009/12)The seafloor can nowadays be scanned with side-looking sonar that provides a very high resolution over a large swath, which has proved beneficial for underwater target detection and classification. For systems operated at ... -
The effectiveness of a system-of-systems for countering asymmetric maritime threats in ports and harbours
(NURC, 2008/09)A small boat loaded with explosives has been used by terrorists to attack military and civilian maritime surface vessels at berth or at anchor. For example, suicide bombers attacked the USS Cole using a small boat while ...