Searched for: author%3A%22Groen%2C+J.%22
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Mourao Vilela, C.F. (author), Gomez-Quero, S. (author), van Zandvoort, I. (author), Lok, M. (author), van Doorn, J. (author), Boymans, E.H. (author), Groen, J. (author), Shijaz, H. (author)
report 2021
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Duijn, M. (author), Groen, J. (author), Nijberg, C. (author), van der Pol, J. (author)
Recentelijk bleek dat Nederland nog steeds daalt op de wereldranglijst van meest innovatieve landen. Een manier om deze trend om te buigen, is het delen van ervaringen met het slechten van belemmeringen bij innovaties. Op die manier kunnen toekomstige innovatieprojecten slimmer ingericht en uitgevoerd worden. Dit artikel presenteert een raamwerk...
article 2010
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Groen, J. (author), Hansen, R.E. (author), Callow, H.J. (author), Sabel, J.C. (author), Sæbø, T.O. (author), TNO Defensie en Veiligheid (author)
Abstract—A shadow cast by an object on the seafloor is important information for target recognition in synthetic aperture sonar (SAS) images. Synthetic aperture imaging causes a fundamental limitation to shadow clarity because the illuminator is moved during the data collection. This leads to a blend of echo and shadow, or geometrical fill-in in...
article 2009
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de Theije, P.A.M. (author), Groen, J. (author), Sabel, J.C. (author), TNO Defensie en Veiligheid (author)
This paper focesus on single-ping classification of sea mines, at a range of about 400 m, and combining a hull mounted sonar (HMS) and a propelled variable-depth sonar (PDVS). The deleoped classifier is trained and tested on a set of simulated realistic echoes of mines and non-mines. As the mines ate too far away for image-based classification,...
conference paper 2006
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de Theije, P.A.M. (author), Groen, J. (author), TNO Defensie en Veiligheid (author)
This paper describes a simulated data set that can be used for tracker evaluation. The data set is generated in the framework of the Multistatic Tracking Working Group (MSTWG). The simulations are carried out using the TNO SIMONA simulator, which can generate raw hydrophone data for an arbitrary number of sources, receivers, and targets. All of...
conference paper 2006
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Lam, F.P.A. (author), Konijnendijk, N.J. (author), Groen, J. (author), Simons, D.G. (author), TNO Defensie en Veiligheid (author)
Simulation of acoustic data is a powerful tool for developing and testing sonar signal processing. This paper describes how TNO’s simulator SIMONA is extended with realistic background reverberation, including wideband (non- Rayleigh) statistics of the signal. The statistical behavior of the received signals changes when multipath is present....
conference paper 2006
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TNO Defensie en Veiligheid (author), Groen, J. (author)
doctoral thesis 2006
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Robert, M.K. (author), Groen, J. (author), Konijnendijk, N.J. (author), TNO Defensie en Veiligheid (author)
The development of undersea defence technologies such as sonar relies heavily on the availability of high quality acoustic data. However, data acquisition is particularly expensive as sea trials involve experienced manpower and costly high-tech equipment. Also, at sea, the environment remains unpredictable and many disturbing effects are...
conference paper 2005
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Groen, J. (author), Beerens, S.P. (author), Been, R. (author), Doisy, Y. (author), TNO Defensie en Veiligheid (author)
Abstract—For a low-frequency active sonar (LFAS) with a triplet receiver array, it is not clear in advance which signal processing techniques optimize its performance. Here, several advanced beamformers are analyzed theoretically, and the results are compared to experimental data obtained in sea trials. Triplet arrays are single line arrays with...
article 2005
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Quesson, B.A.J. (author), Schippers, P. (author), Groen, J. (author), Sabel, J.C. (author), Driessen, F.P.G. (author), TNO Defensie en Veiligheid (author)
The underwater acoustics group at TNO Defense, Security and Safety has developed two simulation software programs named ALMOST and SIMONA. The first is already commercially used and aims at sonar performance prediction, whereas the second one is used as a tool to generate simulated data for mine hunting scenarios with the aim to test different...
conference paper 2005
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Hansen, R.E. (author), Callow, H.J. (author), Saebo, T.O. (author), Groen, J. (author), Quesson, B.A.J. (author), Sabel, J.C. (author), TNO Defensie en Veiligheid (author)
An acoustic simulator is vital for the development of sonar data processing. The most important features in the TNO 3D simulator SIMONA are detailed target response including shadow, reverberation modelling, sonar properties and multipath. The verification and development of SIMONA was realized alongside with a wide range of measurements in a...
conference paper 2005
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Sabel, J.C. (author), Groen, J. (author), Quesson, B.A.J. (author), TNO Defensie en Veiligheid (author)
The acoustic shadow of a target is a strong classification clue in naval mine hunting. A shadow of bottom targets appears at relatively short ranges (≤ about 200 m) in high resolution images from sidescan or synthetic aperture sonar (SAS), against a background of sea floor reverberation. In SAS however, definition of the shadow reduces with...
conference paper 2005
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Colin, M.E.G.D. (author), Groen, J. (author), Quesson, B.A.J. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Although Low Frequency Active Sonar (LFAS) is considered one of the best means of detection and localization of a submarine in shallow water, the use of an active system is not always possible for tactical reasons. It is therefore interesting to include a passive mode in these systems by using the receiving array as a passive array. However,...
conference paper 2004
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Groen, J. (author), Beerens, S.P. (author), Doisy, Y. (author), TNO Fysisch en Elektronisch Laboratorium (author)
ASW operations have shifted toward shallow water environments, where water space is limited and manoeuvring an essential part of operations. The problem that is tackled in this article is the performance loss due to the shape and motion of a manoeuvring sonar. Standard beamforming in towed sonar arrays is based on the assumption that all...
conference paper 2004
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Groen, J. (author), Beerens, S.P. (author), Doisy, Y. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Anti Submarine Warfare (ASW) is more and more focused toward shallow water environments. Many complications have come up for ASW sonar performance as a result of this. The problem that is tackled in this article is the performance loss due to the shape and motion of the sonar during a maneuver. Standard beamforming in towed sonar arrays is based...
conference paper 2004
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TNO Fysisch en Elektronisch Laboratorium (author), Colin, M.E.G.D. (author), Quesson, B.A.J. (author), Hetet, A. (author), Groen, J. (author), Sabel, J.C. (author), Zerr, B. (author), Brusieux, M. (author), Legris, M. (author)
In September 2002, GESMA and TNO-FEL carried out a sea trial with a low frequency (20 kHz) sonar mounted on a mine hunter. The objective of the experiments was to collect sonar echoes from proud and buried objects for subsequent synthetic aperture processing. A large data set was collected, consisting of sonar data from several SAS modes and...
conference paper 2004
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TNO Fysisch en Elektronisch Laboratorium (author), Legris, M. (author), Groen, J. (author), Sabel, J.C. (author), Bellec, R. (author), Amate, M. (author), Hete, A. (author), Zerr, B. (author)
In September 2002, TNO-FEL and GESMA carried out a sea experiment with a low frequency (20 kHz) sonar mounted on a mine hunter. To our knowledge, it is the first time the synthetic aperture sonar technique has been implemented on board an operational mine hunter for the purpose of buried mines detection. The collected data set is mainly made up...
conference paper 2004
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Groen, J. (author), Hansen, R.E. (author), Sabel, J.C. (author), TNO Fysisch en Elektronisch Laboratorium (author)
In the next generation of mine hunting sonars, in particular on Autonomous Underwater Vehicles (AUVs), Synthetic Aperture Sonar (SAS) will play an important role. The benefit of SAS is to increase resolution and signal-tonoise ratio by coherent processing of successive pings. A challenge in SAS is the computational load. This is caused primarily...
conference paper 2003
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Colin, M.E.G.D. (author), Groen, J. (author), TNO Fysisch en Elektronisch Laboratorium (author)
An important issue in research on passive ASW operations is improvement in signal-to-noise ratio (SNR) and bearing resolution for targets emitting low frequency signals. One of the techniques believed to improve these characteristics is Synthetic Aperture Sonar (SAS). The method is based on the artificial enlargement of a sonar array by...
conference paper 2002
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Groen, J. (author), Sabel, J.C. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Synthetic Aperture Sonar uses coherent integration of successive pings to enhance the resolution of side looking sonar. In this paper three diffelent SAS methods are applied to obtain high-resolution images. The first method is applied ping by ping in the frequency domain, whereas the second and third method are applied in the wavenumber...
article 2002
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