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Now showing items 11-20 of 24
Cooperative robotic networks for underwater surveillance: an overview
(CMRE, 2019/06)
Underwater surveillance has traditionally been carried out by means of surface and undersea manned vessels equipped with advanced sensor systems. This approach is often costly and manpower intensive. Marine robotics is an ...
Application of aided inertial navigation system to synthetic aperture sonar micronavigation
(NATO. SACLANTCEN, 2001/01)
In order to improve short-term navigational accuracy, critical to successful SAS processing, a highquality Inertial Navigation System (INS) is investigated, which consists of an inertial measurement unit (IMU) and a strapdown ...
Sub-bands beam-space adaptive beamformer for port-starboard rejection in triplet sonar arrays
(CMRE, 2019/05)
This paper addresses the problem of Port-Starboard (PS) beamforming for low-frequency active sonar (LFAS) with a triplet receiver array. The paper presents a new algorithm for sub-bands beam-space adaptive beamforming with ...
Incoherent sub-band averaging for improved target detection and Doppler estimation in linearly frequency modulated continuous active sonar
(CMRE, 2019/05)
Linear frequency modulated (LFM) continuous active sonar (CAS) waveforms show promise for use in target tracking given that waveforms can be split into sub-waveforms (sub-bands), thereby increasing the target refresh rate. ...
A market-based task allocation framework for autonomous underwater surveillance networks
(CMRE, 2019/06)
Realisation of underwater robotic surveillance networks raises several challenges for marine robotics. The underwater scenario is typically characterised by intermittent and unreliable communication. This makes it challenging ...
A classification technique combining aspect dependence and elastic properties of target scattering
(NATO. SACLANTCEN, 1999/04)
Discrimination between man-made and natural underwater objects and between man-made objects of different characteristics are the key objectives of target classication. The current approach is mainly based on the analysis ...
Localization of small surface vessels through acoustic data fusion of two tetrahedral arrays of hydrophones
(CMRE, 2014/01)
Detection and tracking of vessels is important in confined areas such as marine parks or harbors. Nowadays, the presence of ships can be accurately monitored either by radar or via AIS system, while small vessels, which ...
Adaptive filter of seabed clutter onboard the AUVs of an active multistatic sonar network
(CMRE, 2019/05)
This work aims at reducing the false alarm rate of a multistatic active sonar working in coastal, shallow waters. The sonar system is implemented through a heterogeneous manned-unmanned network including autonomous underwater ...
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 ...