Searched for: mods_originInfo_publisher_s%3A%22Nexus%255C%2BMedia%255C%2BLtd%22
(1 - 20 of 30)

Pages

List view
Grid view
document
Laterveer, R. (author), Beerens, S.P. (author), van IJsselmuide, S.P. (author), Snyder, M. (author), Newcomb, J. (author), TNO Fysisch en Elektronisch Laboratorium (author)
As part of a program to study the effect of man-made noise on marine mammals an EARS Acoustic Recording System) buoy was deployed in the Ligurian sea. The EARS buoy was deployed at a position with a high probability of marine mammal activity at a depth of around 950 m. It was operating for almost 19 days and collected acoustic data sampled at...
conference paper 2004
document
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
document
Benders, F.P.A. (author), Beerens, S.P. (author), Verboom, W.C. (author), TNO Fysisch en Elektronisch Laboratorium (author)
World-wide a concern exists about the influence of man-made noise on marine life, and particularly of high power sonar. Most concern lies with marine mammals that use acoustics for hunting, communication and/or navigation. This concern is fed by recent strandings of whales that could be related to military sonar transmissions and seismic...
conference paper 2004
document
Beerens, S.P. (author), van IJsselmuide, S.P. (author), van Koersel, A.C. (author), TNO Fysisch en Elektronisch Laboratorium (author)
In the current sensor suites on board submarines the Passive Ranging Sonar (PRS) is a separate sensor, usually with three or more hydrophone groups on either side of the submarine. The aperture of this sensor is limited by the length of the boat, which makes ranging up to moderate distances possible. The combination of the towed and flank array...
conference paper 2003
document
Schippers, P. (author), Benders, F.P.A. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Since 1987 sonar performance modelling is developed at TNO Physics and Electronics Laboratory. This is based on propagation modelling in a given environment together with modelling of the sonar based on its specific parameters. Beam forming, pulse type and signal processing are taken into account. The ray based model computes reverberation and...
conference paper 2003
document
Robert, M.K. (author), van Walree, P.A. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Lately, acoustic data transfer has become an important topic in underwater environments. Several acoustic communication signals e.g. spread spectrum or frequency shift keying signals have been extensively developed. However, in challenging environments, it is still difficult to obtain robust acoustic links exceeding a data rate of 1 kbit/s....
conference paper 2003
document
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
document
van IJsselmuide, S.P. (author), Beerens, S.P. (author), Doisy, Y. (author), Deruaz, L. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Low Frequency Active Sonar (LFAS) systems are originally designed for ASW purposes. Although their main purpose is detection of submarines, they can, if adjusted waveforms are transmitted, also be used for detection of small fast moving targets (torpedoes). In this study the Detection, Classification and Localisation performance of classical HFM...
conference paper 2003
document
Benders, F.P.A. (author), Beerens, S.P. (author), Verboom, W.C. (author), TNO Fysisch en Elektronisch Laboratorium (author)
World-wide a concern exists about the influence of man-made noise on marine life, and particularly of high power sonar. Most concern lies with marine mammals that use acoustics for hunting, communication and/or navigation. This concern is fed by recent strandings of whales that could be related to military sonar transmissions and seismic...
conference paper 2002
document
Benders, F.P.A. (author), Witberg, R.R. (author), Grootendorst, H.J. (author)
Several years ago, TNO-FEL started the development of the Torpedo Defence System Testbed (TDSTB) based on the TORpedo SIMulation (TORSIM) model and the Maritime Operations Simulation and Evaluation System (MOSES). MOSES provides the simulation and modelling environment for the evaluation and validation of systems, concepts and tactics in the...
conference paper 2002
document
Grootendorst, H.J. (author), Benders, F.P.A. (author), Driessen, F.P.G. (author), Witberg, R. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The validated TORSIM (TORpedo SlMulation) model simulates the behaviour and determines the effectiveness of different torpedo types (MK46 and MK48), launched from a surface ship, from an air vehicle or from a submarine , against different types of submarine s or surface ships. Evasive manoeuvres of the submarine and the surface ship are included...
conference paper 2002
document
Lentze, S.G. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The TNO underwater warfare (UWW) research programme results in a large number of models used in operational research projects. To enhance the accessibility and re-use of these models for new projects, TNO-FEL has developed the modelling environment ‘MOSES - Maritime Operations Simulation and Evaluation System’. This research environment is based...
conference paper 2001
document
van den Brink, M. (author), Dobson, M. (author), Maclachlan, A. (author), Vermeulen, J.F.J. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Four years ago several NATO nations agreed to commence studies to develop tactics for ASW Area Search. The combined approach required agreement on the scope of the problem, tactical doctrine, modelling parameters and definition of terms. The NATO Area Search and Screening Working Group (AS2WG) is progressing development of tactics with a...
conference paper 2000
document
Doisy, Y. (author), Deruaz, L. (author), Prunel, B. (author), Been, R. (author), Beerens, S.P. (author), van IJsselmuide, S.P. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The influence of the waveform of the transmitted signal on the signal to reverberation ratio of a moving sonar array is analysed on an experimental basis. Experiments have been conducted during sea-trials in shallow water environments in September 98 and October 99. The aim of the trials was to compare the performance of three waveforms:...
conference paper 2000
document
Bergh, A. (author), Beckers, A.L.D. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The Royal Norwegian Navy (RNON) and the Royal Netherlands Navy (RNLN) are both in the process of acquiring new mine sweeping systems which are capable of operating in traditional Mine Setting Mode (MSM), but are also capable of operating in Target Simulation Mode (TSM). TSM sweeping is a new philosophy. Although target simulation sweeping is in...
conference paper 2000
document
Beerens, S.P. (author), Been, R. (author), Groen, J. (author), Noutary, E. (author), Doisy, Y. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Triplet arrays are single line arrays with three hydrophones on a circular section of the array. The triplet structure provides immediate port-starboard (PS) discrimination. This paper discusses the theoretical and experimental performance of triplet arrays. Results are obtained on detection gain and PS discrimination in several environmental...
conference paper 2000
document
Volwerk, C. (author), Been, R. (author), Kromjongh, J. (author), Jarvis, A.K. (author), TNO Fysisch en Elektronisch Laboratorium (author)
Quieter targets imply longer sonar arrays for improved detection performance. Straight-line assumptions in the beamforming process are no longer valid and it becomes important to know the actual hydrophone positions. Knowing the shape and attitude of a hydrophone array with sufficient accuracy enables correction of the beamwidth and sidelobe...
conference paper 2000
document
Been, R. (author), Beerens, S.P. (author), van IJsselmuide, S.P. (author), Prunel, B. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The influence of the waveform of the transmitted signal on the signal to reverberation ratio of a moving sonar array is analysed on an experimental basis. Experiments were conducted during sea-trials in shallow water areas in September 98 and October 99. The aim of the trials was to compare the performance of three waveforms: frequency modulated...
conference paper 2000
document
Lentze, S.G. (author), Benders, F.P.A. (author), Dekker, J.J.M. (author), TNO Fysisch en Elektronisch Laboratorium (author)
The sonar performance indicator (SPI) will be an integral part of the modernised command and control system of the RNIN Alkmaar class minehunters. The SPI will act as a tactical decision aid, supporting both the detection sonar operator as well as the commanding officer, for the hull mounted sonar (HMS) as well as the propelled variable depth...
conference paper 1999
document
Beerens, S.P. (author), van IJsselmuide, S.P. (author), Volwerk, C. (author), Trouve, E. (author), Doisy, Y. (author), TNO Fysisch en Elektronisch Laboratorium (author)
In the design of towed array sonar the reduction of flow noise is an important issue. In this paper flow noise theory and several methods to analyse flow noise are presented. These methods are applied to sea trial data of an experimental triplet array. The obtained results agree very well with accepted theory. It appears that the methods in...
conference paper 1999
Searched for: mods_originInfo_publisher_s%3A%22Nexus%255C%2BMedia%255C%2BLtd%22
(1 - 20 of 30)

Pages

List view
Grid view