Browsing Technical Reports by Title
Now showing items 151-170 of 322
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Interpretation and representation of the synoptic features in the Iceland-Faeroe-Shetland region
(NATO. SACLANTCEN, 1993/07)The kinematic structure of the sub-inertial fluctuations of measured current and temperature fields from 6 moorings deployed during the June -
Inverse acoustical determination of photosynthetic oxygen productivity of Posidonia seagrass
(NATO. SACLANTCEN, 2000/02)As part of geoacoustic inversion experiments (Yellow Shark) in the Giglio basin, off the west coast of Italy, low frequency, broad-band propagation measurements were performed in the winter and spring of 1995 over a dense ... -
Inversion for geometric and geoacoustic parameters in shallow water: experimental results
(NATO. SACLANTCEN, 1994/12)Experimental results on the estimation of both geometric and geoacoustic parameters in shallow water are presented. Genetic algorithms are used for estimation of the forward model parameters, the -
Inversion of broad-band multitone acoustic data from the YELLOW SHARK summer experiment
(NATO. SACLANTCEN, 1997/09)Integral geoacoustic properties of the sea bottom were determined from full-field inversion of broad-band, waterborne, acoustic propagation data. The data were obtained during the YELLOW SHARK 94 experiment along a 15-km ... -
Inversion of seismo-acoustic data using genetic algorithms and 'a posteriori' distributions
(NATO. SACLANTCEN, 1993/08)The goal of many underwater acoustic modelling problem is to establish the physical parameters of the environment. With the increase in -
Inversion of seismo-acoustic real data using genetic algorithms
(NATO. SACLANTCEN, 1994/03)An inversion scheme for the estimation of the physical parameters -
Limitations on towed array gain imposed by a non-isotropic ocean
(NATO. SACLANTCEN, 1990/08)This study deals with the limitations imposed by ocean characteristics on hydrophone array gain and on attempts to create a synthetic aperture using towed-array measurements. The multi-element synthetic or physical aperture ... -
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 ... -
Long range, large throughput radio data links for DUSS (Deployable Underwater Surveillance Systems)
(NATO. SACLANTCEN, 1999/10)Two mono-directional radio telemetry systems are described operating from a buoy to NRV Alliance at frequencies of 0.4 and 2.28 GHz. Digital data at 2 Mbps were transmitted close to the sea surface, collecting information ... -
Low frequency active sonar: a NATO Conference held by SACLANTCEN on 24-28 May 1993 - collection of unclassified papers - volume 1 of 2
(NATO. SACLANTCEN, 1993/08)A conference on Low Frequency Active Sonar was held at SACLANTCEN from 24th to 28th May 1993. The conference was attended by over 100 delegates from NATO countries, and the topics presented ranged from environmental aspects, ... -
Low frequency active sonar: a NATO Conference held by SACLANTCEN on 24-28 May 1993 - collection of unclassified papers - volume 2 of 2
(NATO. SACLANTCEN, 1993/08)A conference on Low Frequency Active Sonar was held at SACLANTCEN from 24th to 28th May 1993. The conference was attended by over 100 delegates from NATO countries, and the topics presented ranged from environmental aspects, ... -
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 -
MAKE-MAP and MEDMAP: two programs for plotting maps of the Mediterranean Sea
(NATO. SACLANTCEN, 1988/06)Two FORTRAN programs MAKE_MAP and MEDMAP are described which, when used together, will plot maps of all or any portion of the Mediterranean Sea. Examples are given which show the high degree of detail provided by the 2' ... -
Mapping ocean sediments by RBF networks
(NATO. SACLANTCEN, 1992/09)Interpolation of sparse measurements of ocean-sediment properties by generalized radial basis function (RBF) networks is proposed. An RBF -
Measurements and predictions of transmission loss at two sites in the Southwest Approaches to the English Channel
(NATO. SACLANTCEN, 1995/12)As part of a continuing series of measurements being made by -
Measurements for satellite validation made from the RV Alliance during October and November 1991
(NATO. SACLANTCEN, 1993/08)Measurements of sea-surface temperature, surface meteorology and atmospheric profiles were taken from the RV Alliance between 1 October -
Measurements of acoustic scattering from partially and completely buried spherical shells
(NATO. SACLANTCEN, 1999/04)Recent work at NATO SACLANT Undersea Research Centre has concentrated on investigating the use of low frequency sonars (2-20 kHz) in order to better exploit scattering features of buried targets that can contribute to their ... -
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 ... -
Mechanisms for subcritical penetration into a sandy bottom: experimental and modelling results
(NATO. SACLANTCEN, 1998/05)This paper presents the results of a recent study whose overall objectives are to determine the mechanism(s) contributing to subcritical acoustic penetration into ocean sediments, and to quantify the results for use in ... -
Mixed layer deepening and variability in the upperlayers if the central western Mediterranean, MILEX-82: final report
(NATO. SACLANTCEN, 1988/10)The 1982 Mixed-Layer Experiment (MILEX-82) is described in detail and the data are presented in ways designed to illustrate the spatial and temporal variability of the surface and deeper layers of the central western ...