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Now showing items 281-300 of 882
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Spatial variability of surficial shallow water sediment geoacoustic properties
(NATO. SACLANTCEN, 1986/06)Variability of surficial sediment geoacoustic properties was determined from cores collected at eight shallow-water continental shelf regions in the U.S., Italy and Australia. Highly porous muds found in low energy ... -
Fast Fourier transformation algorithms: experiments with microcomputers
(NATO. SACLANTCEN, 1986/07)We describe experiments intended to exploit the potential of modern -
Application of beam-forming techniques to measurements of acoustic scattering from the ocean
(NATO. SACLANTCEN, 1986/10)Signals from an explosive source backscattered from the seafloor and received at long range by -
High-resolution beamforming techniques performance analysis
(NATO. SACLANTCEN, 1986/11)Seven different beamforming techniques (including both conventional and high-resolution types) have been analyzed and compared in order to develop a quantitative relationship between resolution performance on the one hand ... -
An analysis of selected satellite data of the Aegean area with the STARS software
(NATO. SACLANTCEN, 1986/11)Data from selected orbits of the NOAA-7 meteorological satellite are used for an exploratory analysis -
Target motion effects on passive sonar: an appraisal of basic factors
(NATO. SACLANTCEN, 1986/12)Detection and tracking by passive sonar involve the observation of the target-radiated noise in bearing-cells and time-cells that have their dimensions predetermined by a combination of physical limitations, e.g. the size ... -
Measurements of correlation loss and time-spreading in linear FM sweeps and pseudo-random noise signals transmitted over long ranges in shallow water
(NATO. SACLANTCEN, 1986/12)The results of some transmission measurements made in shallow water are described. The ranges were about 15 km, 20 km, and 34 km, and the sound source was either suspended about 10 m above the bottom or was on the bottom ... -
Logarithmic least mean square sound-field estimation
(NATO. SACLANTCEN, 1987/03)The report deals with narrowband beamforming techniques for passive sonar applications. In particular, the Least Mean Square fit parameter estimation technique is used to estimate the spatial sound-field power density. To ... -
Studies on information mechanics
(NATO. SACLANTCEN, 1987/04)Related issues connected with the transmission of information in a command and control environment -
The application of coupled-mode theory to propagation in shallow water with randomly varying sound speed
(NATO. SACLANTCEN, 1987/06)Sound propagation in the Baltic Sea cannot be described correctly by range independent propagation -
Passive localization using propagation models
(NATO. SACLANTCEN, 1987/06)Passive ranging using propagation models can be effected in two different ways: forward modeling -
Wave theory modelling of convergence zone propagation in the ocean
(NATO. SACLANTCEN, 1987/06)Improved numerical techniques together with continual advances in computer technology have now -
A collection of analytical results related to the ASW protection of convoys and carriers
(NATO. SACLANTCEN, 1987/07)This paper is a collection of diverse analytical results that are related to several aspects of a common problem: the defence of carriers against torpedo-firing submarines. This work is not in any sense a complete treatment ... -
A method for determining absolute velocities from hydrographic data
(NATO. SACLANTCEN, 1987/07)This study describes a procedure for deriving the characteristics of large-scale climatic currents from -
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 -
Deep water mass circulation in the Alboran basin: measurements - January to April '82 ALBORAN II
(NATO. SACLANTCEN, 1987/09)Alboran Sea circulation between 220 m and 1100 m depth is studied. Interaction between three water types, Atlantic water, Levantine water, and western Mediterranean Deep water cause a complicated flow pattern. Atlantic ... -
Low-frequency reverberation measurements with an activated towed array: Scattering strengths and statistics
(NATO. SACLANTCEN, 1987/10)Results of reverberation measurements made with a low-frequency activated towed array sonar system in two deep-water locations of the Mediterranean Sea are presented. Measurements took -
Testing finite differencing schemes for the shallow water equations
(NATO. SACLANTCEN, 1987/10)The explicit, the semi-implicit, and the fractional step schemes are tested and compared in the -
The effects of atmospheric and thermohaline variability on the validation of the GEOSAT altimeter oceanographic signal between Scotland and Iceland
(NATO. SACLANTCEN, 1987/10)Atmospheric and oceanographic profiles from the area between Scotland and Iceland are analysed in -
Alternative approach to passive sonar
(NATO. SACLANTCEN, 1987/10)An alternative approach to spatial processing for passive sonar is proposed and discussed. It is