Browsing by Issue Date
Now showing items 681-700 of 882
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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 ... -
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 ... -
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 ... -
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 ... -
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, ... -
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 ... -
High resolution sonar (tutorial slides)
(NURC, 2010/07) -
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 ... -
2009 Research and Technology Highlights
(NURC, 2010/08) -
Waterside Security 2010 (WSS2010) conference: post conference report
(NURC, 2011/02)The 2nd International Conference on Waterside Security was hosted by NURC, Carrara, Italy, 3-5 November 2010. This report provides summary statistics of the conference, a summary of the workshops, remarks form the WSS2010 ... -
2010 Research and Technology Highlights
(NURC, 2011/08) -
On adaptive underwater object detection
(NURC, 2012/04)A new algorithm for the detection of underwater objects in sonar imagery is proposed. One particularly novel component of the algorithm also detects the presence of, and estimates the orientation of, sand ripples. The ... -
Volumetric distribution of oceanographic fields estimated from remote sensing and in situ observations from autonomous underwater vehicles of opportunity
(NURC, 2012/04)A main challenge of military oceanography (MILOC) is to assess the oceanographic conditions of denied/highrisk marine regions. Monitoring technologies are limited to those that can provide access to these regions. Remote ... -
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 ... -
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 ... -
AUV-enabled adaptive underwater surveying for optimal data collection
(NURC, 2012/04)A new adaptive strategy for performing data collection with a sonar-equipped autonomous underwater vehicle (AUV) is proposed. The approach is general in the sense that it is applicable to a wide range of underwater tasks ...