Browsing by Title
Now showing items 581-600 of 882
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A paradigm shift of interoperable submarine rescue operations: the usage of JANUS during the Dynamic Monarch 2017 exercise
(CMRE, 2019/05)The NATO Centre for Maritime Research and Experimentation (CMRE) participated for the first time in the Dynamic Monarch submarine rescue exercise, bringing to the operational players a new interoperable digital underwater ... -
Parameter estimation using multi-frequency range-dependent acoustic data in shallow water
(NATO. SACLANTCEN, 1996/11)The estimation of all forward model parameters - geometric, geoacoustic, -
Parametric relations on FM sonar
(NATO. SACLANTCEN, 1961/06)The report deals with the simple theory of FM sonar operations and shows how an optimum system may be designed. It also indicates the effects of doppler, the equipment and other factors which may be expected, in practice, ... -
Passive acoustic detection of marine mammals
(NATO. SACLANTCEN, 2000/04)A passive acoustic analysis of data recorded during the SACLANTCEN -
Passive acoustic surveillance of surface vessels using tridimensional array on an underwater glider
(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 ... -
Passive localization using propagation models
(NATO. SACLANTCEN, 1987/06)Passive ranging using propagation models can be effected in two different ways: forward modeling -
Passive ranging with the SNAP model: a performance study
(NATO. SACLANTCEN, 1987/07)A passive ranging technique which uses SNAP, the SACLANT Centre's normal-mode model, is studied. An examination is made of the sensitivity of the technique to errors in the assumed sound -
PC-based propagation and sonar prediction models
(NATO. SACLANTCEN, 1995/12)Six acoustic models available for use on PC's are tested on a series of typical propagation situations from the North Atlantic and the Mediterranean. The model set includes both early US Navy models (ASTRAL, FACT, RAYMODE) ... -
Penetration of acoustic waves into sandy seafloors at low grazing angles: the Helmholtz-Kirchhoff approach
(NATO. SACLANTCEN, 1998/08)The Helmholtz-Kirchhoff integral is applied to model the penetration of sound waves into sandy seafloors at grazing angles above and below the critical angle. Although the conditions for the validity -
Performance assessment of broadband impulsive noise jammers
(NATO. SACLANTCEN, 1993/08)A noise jammer raises the noise level observed by a threat sonar to degrade the sonar's detection performance. In this paper we assess the potential for a specific noise jammer waveform used to countermeasure low frequency ... -
Performance assessment of propagation models in AESS-6.0
(NATO. SACLANTCEN, 1999/08)A set of AESS propagation-loss predictions has been generated for typical operational scenarios in both deep and shallow water, for two sonar frequencies (500 and 3500 Hz) and for several source-receiver combinations. ... -
Performance assessment of the LYBIN - 2.0 propagation-loss model
(NATO. SACLANTCEN, 2001/07)A new acoustic model LYBIN has been proposed for inclusion in the AESS model set. In order to determine this model's prediction accuracy and computational efficiency, SACLANTCEN was tasked to test LYBIN on exactly the same ... -
Performance assessment of the MUSCLE synthetic aperture sonar
(CMRE, 2014/01)Synthetic Aperture Sonar (SAS) systems are quickly becoming fundamental tools for seabed mapping applications, as they provide high resolution imagery independent of range from the sensor, with high area coverage rates. ... -
Performance assessment of the SACLANTCEN vertical array in shallow water
(NATO. SACLANTCEN, 1994/03)In this memoranduin the performance of the SACLANTCEN vertical -
Performance assessment of vessel dynamic models for long-term prediction using heterogeneous data
(CMRE, 2019/06)Ship traffic monitoring is a foundation for many maritime security domains, and monitoring system specifications underscore the necessity to track vessels beyond territorial waters. However, vessels in open seas are seldom ... -
Performance evaluation of underwater medium access control protocols: at-sea experiments
(CMRE, 2019/06)In this paper, we investigate the performance of three medium access control (MAC) protocols (CSMA, TLohi, and DACAP) representing simple, intermediate, and fully negotiated protocols, to access the underwater acoustic ... -
Performance of three averaging methods for various distributions
(NATO. SACLANTCEN, 1982/06)The performance of three averaging methods, namely the sample median, the sample arithmetic mean, and the sample geometric mean, are analyzed in tenns of their bias, variance, and mean square error. The bias and variance ... -
Perturbation theory applied to sound scattering from a rough sea-floor
(NATO. SACLANTCEN, 1992/09)Perturbation theory is applied to acoustic scattering from a rough sedimental sea-floor. Realistic -
Physical and dynamical characteristics of a 300 m-deep anticyclonic eddy in the Ligurian Sea (Northwest Mediterranean Sea): evidence from a multi-platform sampling strategy
(CMRE, 2019/06)We describe the physical and dynamical characteristics of a mesoscale anticyclonic eddy observed in August 2013 over the shelf-break region of the northeastern sector of the Ligurian Sea, between the northeastern edge of ... -
Physics of 3-D scattering from rippled seabeds and buried targets in shallow water
(NATO. SACLANTCEN, 1998/05)The new OASES-3D code developed at MIT is used to investigate the spatial and temporal characteristics of reverberation from rippled seabeds insonified by narrow beam sonars such as the TOPAS parametric source. It is shown ...