CMRE Publications: Recent submissions
Now showing items 381-400 of 882
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DUSS97: source localization and environmental inversion using vertical array data
(NATO. SACLANTCEN, 1998/08)Results on source localization and environmental inversion using experimental data acquired on a vertical line array are presented. Global inversion methods based on genetic algorithms are utilized to estimated the range ... -
The application of parametric side scan sonar to the detection of proud and buried targets
(NATO. SACLANTCEN, 1998/01)This paper describes an experiment designed to evaluate the feasibility of using the TOPAS parametric transmitter mounted in side scan mode, for the detection of buried targets. The concept was tested with proud targets ... -
Broadband geo-acoustic inversion from sparse data using genetic algorithms: results from the 1997 Geo-Acoustic Inversion Workshop
(NATO. SACLANTCEN, 1998/03)Matched field acoustic inversion techniques were investigated -
Development of a SACLANTCEN MCM sonar performance model
(NATO. SACLANTCEN, 1996/11)The report describes the Mine Countermeasures Sonar Performance -
On the physics and design of electrical discharge sources for active undersea surveillance
(NATO. SACLANTCEN, 1993/08)Underwater electrical arcs have long been used as an impulsive sound source, although efforts to improve efficiency and control acoustic output have been limited by inadequate understanding of the arc initiation process. ... -
Array and cable tracking data through ship maneuvers
(NATO. SACLANTCEN, 1993/08)This paper presents tracking results from two sea tests in which a towed cable and array were tracked at the Atlantic Undersea Test and Evaluation Center (AUTEC). The tracking tests involved instrumenting the cable with ... -
Array shape determination with a real-time model
(NATO. SACLANTCEN, 1993/08)A shape estimation scheme based on precomputed frequency-domain solutions of array motion is presented. The boundary conditions supporting each solution are discrete Fourier transform (OFT) components of sensor measurements, ... -
Practical active sonar receiver systems using fast frequency-domain correlation
(NATO. SACLANTCEN, 1993/08) -
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 ... -
Channel sensitive processor: sensitivity and optimization study
(NATO. SACLANTCEN, 1997/10)The detection performance of the Channel-Sensitive Processor (CSP) has been tested in dense multipath conditions. It was demonstrated that, for a known propagation channel, the CSP outperforms the conventional matched ... -
An approach to robust map generation from multibeam bathymetric data
(NATO. SACLANTCEN, 1997/10)During the last twenty years, many multibeam bathymetric sonars have been produced. The instrumentation is usually accompanied by a system able to produce a seafloor map from the sonar data. There are also several public ... -
Channel sensitive processor: real data processing
(NATO. SACLANTCEN, 1998/02)The CSP is applied to data collected during the DUSS97 sea trial. A one-way geometry is used and the transmitted signal propagation time is known a priori. As predicted by analytical and simulation studies, the CSP detector ... -
The hydrological characteristics of the waters exchanged between the eastern and the western basins of the Mediterranean
(NATO. SACLANTCEN, 1972/09)An analysis is done of hydrographic data obtained in 1965 and 1966 in the region of Tunis-Sicily-Malta. Vertical sections permit to follow the opposite spreadings of the surface water of Atlantic origin and the levantine ... -
A parametric synthetic aperure sonar for detection of proud and buried mines
(NATO. SACLANTCEN, 1997/12)This paper describes an experimental comparison between a parametric sonar and a conventional sonar for the detection of small objects on and in, the sea bed. Two experiments were performed in France (GESMA site) in October ... -
The ocean wave dynamo: a source of magnetic ambient noise
(NATO. SACLANTCEN, 1997/09)The electromagnetic dynamo field of sea surface waves, a consequence of the Lorentz force, has been measured with two simultaneously operating, closely spaced tri-axial magnetometers. Measurements from a magnetometer located ... -
An automated instrument for testing and monitoring oceanographic mooring cables and ropes
(NATO. SACLANTCEN, 1997/09)Underwater acoustic experiments at the NATO SACLANT Undersea Research Centre, La Spezia, Italy (SACLANTCEN) are largely dependent on moored and towed instrumentation. Every year up to 500 cable terminations am made and ... -
Reduction of low frequency active sonar clutter through image processing
(NATO. SACLANTCEN, 1997/12)Large numbers of false clutter detections arise in the use of low frequency active sonar for the detection of low Doppler submarine targets in shallow water. Traditional detection algorithms operate individually on each ... -
Resonance scattering analysis by autoregressive models applied to air-filled, cylindrical, thin walled shells in water
(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 ... -
RAPID RESPONSE, september 1996: modelling of broadband transmission loss along selected tracks in the Strait of Sicily
(NATO. SACLANTCEN, 1997/07)A large set of experimental acoustic broadband data in the 50-3200 Hz band is analyzed with the objective of deriving average geoacoustic models for three sites in the Strait of Sicily. The experimental data were obtained ... -
Comparison of a time domain spectral collocation method and the time-evolution backscatter model BORIS
(NATO. SACLANTCEN, 1997/11)A model based on the time-domain spectral collocation method has been implemented at Forsvarets