Browsing by Issue Date
Now showing items 601-620 of 882
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Passive acoustic detection of marine mammals
(NATO. SACLANTCEN, 2000/04)A passive acoustic analysis of data recorded during the SACLANTCEN -
Mode and PE predictions of propagation in range-dependent environments: SWAM'99 workshop results
(NATO. SACLANTCEN, 2000/05)Three numerical acoustic models, a coupled normal-mode model (C-SNAP), -
Improvements to data networks in support of REA during Generic Oceanographic Array Technology (GOATS) 98
(NATO. SACLANTCEN, 2000/05) -
Characteristics of the mediterranean seagrass Posidonia oceanica contributing to high-frequency acoustic scattering
(NATO. SACLANTCEN, 2000/05)Posidonia oceanica meadows are the most important ecosystem for the life cycle of coastal Mediterranean benthos with a fundamental role in the primary production of the neritic system and a decisive influence on other ... -
A satellite based ocean forecasting system to support naval operations in crisis situations
(NATO. SACLANTCEN, 2000/05)We employ a nonlinear ocean forecasting technique based on a combination of genetic algorithms and empirical orthogonal function (EOF) analysis. The method is used to forecast the space-time variability of the sea surface ... -
On the spatial variability of the impulse response of an underwater acoustic channel
(NATO. SACLANTCEN, 2000/05)In many applications like adaptive equalization, beam-forming, matched field processing or focalization the performance is limited due to changes in the impulse response caused by variations in source-receiver range or in ... -
An automatic approach to ship detection in spaceborne synthetic aperture radar imagery: an assessment of ship detection capability using RADARSAT
(NATO. SACLANTCEN, 2000/12)This report describes a methodology for automated ship and wake detection in space-based synthetic aperture radar (SAR) imagery. The methodology incorporates a multistage approach involving several algorithms which can ... -
Annual Progress Report 2000
(NATO. SACLANTCEN, 2001) -
Application of aided inertial navigation system to synthetic aperture sonar micronavigation
(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 ... -
Seismic stratigraphy of the Capraia basin, Northern Tyrrhenian Sea
(NATO. SACLANTCEN, 2001/01)The distribution and thickness of sediments within the Capraia Basin, Northern Tyrrhenian Sea, have been mapped using high-resolution seismic reflection data. The data were studied within the geologic framework determined ... -
Spectral integral representations of monostatic backscattering from three dimensional distributions of sediment volume inhomogeneities
(NATO. SACLANTCEN, 2001/03)A theory is developed for generating short time, monostatic reverberation realizations caused by three dimensionally distributed volume inhomogeneities in stratified media. A spectral integral approach to treating the ... -
Benchmarking of SCARAB volume scattering versus OASES volume scattering
(NATO. SACLANTCEN, 2001/05)OASES uses wavenumber integration to solve for the backscattered pressure caused by sound speed and density inhomogeneity scatterers in the sediment; SCARAB uses a ray path technique to find the backscattered intensity. ... -
Direct observation of the angle of intromission in marine sediment
(NATO. SACLANTCEN, 2001/06)High porosity marine sediments like silty clays have the curious property that the speed of sound through its bulk medium is lower than that of the interstitial pore fluid. When a high porosity sediment is at the water ... -
Predicting underwater ambient noise with an evolutionary signal processing method
(NATO. SACLANTCEN, 2001/06)In this report we employ recent developments in non-linear physics and time series prediction to study the physical characteristics of measured underwater ambient sounds. Specifically, we examine the predictability of a ... -
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 ... -
Bathymetric imaging with wideband interferometric synthetic aperture sonar
(NATO. SACLANTCEN, 2001/11)A new approach to interferometric sonar is presented, based on time delay estimation using shortterm correlation of the seafloor backscatter. It is most suited to signals with large relative bandwidths and long interferometric ... -
Annual Progress Report 2001
(NATO. SACLANTCEN, 2002) -
Real-and synthetic-array signal processing of buried targets
(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 ... -
Water masses, sound velocity structure and circulation between the eastern Algerian Basin and the Strait of Sicily in October 1996
(NATO. SACLANTCEN, 2002/01)The investigation is based on data collected between the eastern Algerian Basin and the Strait of Sicily and in the southern Tyrrhenian Sea. The major pathways of water masses are identified by the -
Noise measurements during MAPEX 2000
(NATO. SACLANTCEN, 2002/03)During MAPEX2000 some simultaneous ambient noise measurements with an HLA and satellite SAR images were collected. The aim was to predict shipping and wind noise from the satellite radar and to compare results with acoustic ...