Browsing by Author "Tesei, Alessandra"
Now showing items 1-20 of 24
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A classification technique combining aspect dependence and elastic properties of target scattering
Zerr, Benoit; Tesei, Alessandra; Maguer, Alain; Fox, Warren L. J.; Fawcett, John A. (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 ... -
A novel approach for a bistatic scattering calculation suitable for sonar performance model
Canepa, Gaetano; Tesei, Alessandra (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 ... -
Adaptive filter of seabed clutter onboard the AUVs of an active multistatic sonar network
Micheli, Michele; Tesei, Alessandra; Ferri, Gabriele; Stinco, Pietro (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 ... -
Application of aided inertial navigation system to synthetic aperture sonar micronavigation
Tesei, Alessandra; Pinto, Marc A. (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 ... -
At-sea measurements of acoustic elastic scattering by a 1.5m-long cylinder made of composite materials
Tesei, Alessandra; Zampolli, Mario; Canepa, Gaetano (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 ... -
Autonomous underwater surveillance networks: a task allocation framework to manage cooperation
Ferri, Gabriele; Bates, Jeffrey; Stinco, Pietro; Tesei, Alessandra; LePage, Kevin D. (2019/05)The design of efficient task allocation schemes is essential to manage autonomous underwater robotic surveillance networks. The network has to assign the most suited robots to the tasks which compose the mission, in spite ... -
Cooperative robotic networks for underwater surveillance: an overview
Ferri, Gabriele; Munafò, Andrea; Tesei, Alessandra; Braca, Paolo; Meyer, Florian; Pelekanakis, Konstantinos; Petroccia, Roberto; Alves, João; Strode, Christopher; LePage, Kevin D. (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 ... -
Incoherent sub-band averaging for improved target detection and Doppler estimation in linearly frequency modulated continuous active sonar
Bates, Jeffrey; Grimmett, Douglas; Canepa, Gaetano; Tesei, Alessandra (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. ... -
Localization of multiple sources using time-difference of arrival measurements
Meyer, Florian; Tesei, Alessandra; Zwin, Moe Z. (CMRE, 2019/06)This paper addresses the problem of localizing an unknown number of static sources emitting unknown signals from time-difference of arrival (TDOA) measurements. Based on the framework of random finite sets and finite set ... -
Localization of small surface vessels through acoustic data fusion of two tetrahedral arrays of hydrophones
Tesei, Alessandra; Fioravanti, Stefano; Grandi, Vittorio; Guerrini, Piero; Maguer, Alain (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 ... -
A market-based task allocation framework for autonomous underwater surveillance networks
Ferri, Gabriele; Munafò, Andrea; Tesei, Alessandra; LePage, Kevin D. (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 ... -
Measurements and modelling of high-frequency acoustic scattering by a rough seafloor and sea surface
Tesei, Alessandra; Canepa, Gaetano; Zampolli, Mario (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 ... -
Measurements of acoustic scattering from partially and completely buried spherical shells
Tesei, Alessandra; Maguer, Alain; Fox, Warren L. J.; Schmidt, Henrik (NATO. SACLANTCEN, 1999/04)Recent work at NATO SACLANT Undersea Research Centre has concentrated on investigating the use of low frequency sonars (2-20 kHz) in order to better exploit scattering features of buried targets that can contribute to their ... -
On-board real-time assessment of acoustic environmental parameters relevant to the estimation of sonar performance for autonomous underwater vehicles
LePage, Kevin D.; Oddone, Manlio; Micheli, Michele; Strode, Christopher; Tesei, Alessandra (CMRE, 2019/05)CMRE is evaluating the use of autonomous robots for the detection and tracking of underwater targets. Robotic detection and localization comes with many challenges, not the least of which is the requirement to maximize the ... -
Passive acoustic surveillance of surface vessels using tridimensional array on an underwater glider
Tesei, Alessandra; Been, Robert; Cardeira, Bruno; Galletti, Domenico; Cecchi, Daniele; Garau, Bartolome; Maguer, Alain; Williams, David P. (CMRE, 2019/06)The NATO-STO Centre for Maritime Research and Experimentation (CMRE) has proposed to approach the problem of monitoring marine traffic in defined sea areas by using passive acoustics on a mobile underwater platform, in ... -
Real-and synthetic-array signal processing of buried targets
Pinto, Marc A.; Bellettini, Andrea; Hollett, Reginald D.; Tesei, Alessandra (NATO. SACLANTCEN, 2002/01)Results from two field experiments aimed at investigating the detection and classification of buried targets are presented. In both experiments a 2-16 kHz parametric source was used. In the first experiment the source was ... -
Real-time underwater positioning and navigation of an AUV in deep waters
Tesei, Alessandra; Micheli, Michele; Vermeij, Arjan; Ferri, Gabriele; Mazzi, Marco; Grenon, Gabriel; Morlando, Luca; Biagini, Stefano; LePage, Kevin D.; Costanzi, Riccardo; Fenucci, Davide; Caiti, Andrea; Munafò, Andrea (CMRE, 2019/05)Due to the absence of GPS, navigation of autonomous vehicles underwater requires the integration of various measurements to provide the best location estimate. Usually in littoral waters, adequate navigational accuracy may ... -
Recent technological advances in underwater autonomy
Maguer, Alain; Been, Robert; Tesei, Alessandra; Alves, João; Grandi, Vittorio; Biagini, Stefano (2019/05)Underwater Unmanned systems (or more precisely systems of systems) will definitely play an important role in future maritime surveillance and environmental data collection. For many years, the NATO Centre for Maritime ... -
Resonance analysis of the acoustic response of a water-filled cylindrical shell
Tesei, Alessandra; Fawcett, John A.; Fox, Warren L. J.; Maguer, Alain (NATO. SACLANTCEN, 1998/09)The resonance analysis approach developed for characterizing free-field air-filled cylindrical shells in terms of geometrical and mechanical pararneters is extended to fluid-filled shells either in the freefield or proud ... -
Resonance scattering analysis by autoregressive models applied to air-filled, cylindrical, thin walled shells in water
Tesei, Alessandra; Fox, Warren L. J.; Maguer, Alain; Lovik, A. (NATO. SACLANTCEN, 1997/10)Autoregressive (AR) parametric spectral estimation of the scatterer transfer function is applied to the analysis of acoustic scattering by elastic objects. In accordance with Resonance Scattering Theory (RST), the specular ...