Browsing by Title
Now showing items 416-435 of 882
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Intensity moments of underwater sound scattered by a Gaussian spectrum corrugated surface: measurements and comparison with a catastrophe theory approximation
(NATO. SACLANTCEN, 1997)An underwater forward-scattering investigation was undertaken with random rough corrugated pressure release surface manufactured out of Styrofoam. Measured wavefields associated with the reflection caustics agree with ... -
Intensity-range relations for shallow-water sound propagation
(NATO. SACLANTCEN, 1976/04)Convincing experimental evidence is presented to show that various "decay laws" for the decrease of sound intensity with increasing range can give high-quality representation for shallow water data. However, while a sequence ... -
Interactive tools for the exploration and analysis of multibeam and other seafloor acoustic data
(NATO. SACLANTCEN, 1997)The Ocean Mapping Group has developed a full suite of software tools for the real-time or near real-time display, editing, quality control, interpretation and visualization of multibeam sonar data. The combination of ... -
Interface wave studies on the Ligurian shelf usingan OBS array: experimental results and propagation models
(NATO. SACLANTCEN, 1986/06)Seismic waves travelling in the water/sediment or subbottom sediment/sediment interface have been the subject of considerable interest in recent years. Experiments have confirmed the existence of interface waves in different ... -
Interface-wave propagation studies: an example of seismo-acoustic propagation in non-homogeneous materials
(NATO. SACLANTCEN, 1990/01)This study addresses the problem relating to the interaction processes -
Intermediate water downstream of the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)In July 1970 the ATLANTIS II sailed through the western Mediterranean providing an opportunity to make a quasi-synoptic observation of the Levantine Intermediate Water between the Strait of Gibraltar and the Strait of ... -
Internal oceanographic microstructure phenomena
(NATO. SACLANTCEN, 1975/10)This paper is concerned with the nature and causes of both fine structure and microstructure in the ocean. Following an account of the acoustic/oceanographic background to subject, the characteristics of fine structure are ... -
Interpretation and fusion of sonar images using evidential reasoning
(NATO. SACLANTCEN, 1995/12)A method and system architecture for automatic interpretation and fusion of multiple sonar images is proposed. The interpretation of a sonar image consists of the creation of a symbolic geographical map indicating the ... -
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 ... -
Inverse wave propagation in an inhomogeneous waveguide
(NATO. SACLANTCEN, 1975/10)A solution is given for the problem of inverse propagation in an inhomogeneous rectangular two-dimensional waveguide. The sound speed is assumed to vary in depth and inverse propagation means the calculation of the field ... -
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 -
Is power averaging the best estimator for undersea acoustic data?
(NATO. SACLANTCEN, 1982/06)The power average is the statistic which is commonly used in all types of acoustic data processing. It is an excellent estimator for "well behaved" Gaussian distributions when the central or average value is desired. ... -
JANUS-based services for operationally relevant underwater applications
(CMRE, 2017/11)This paper presents the design, test, and experimentation at sea of four JANUS-based services for operationally relevant underwater applications: 1) first contact and language switching; 2) transmission of automatic ... -
Joint probabilistic data association tracker for extended target tracking applied to X-band marine radar data
(CMRE, 2019/06)X-band marine radar systems are flexible and low-cost tools for monitoring multiple targets in a surveillance area. Although they may suffer from several sources of interference, e.g., sea clutter, they can provide ... -
Joint probabilistic data association tracker for extended target tracking applied to X-band marine radar data
(CMRE, 2017/11)X-band marine radar systems are flexible and low-cost tools for monitoring multiple targets in a surveillance area. Although they may suffer from several sources of interference, e.g., sea clutter, they can provide ... -
Knowledge-based ship tracking applied to HF surface wave radar data
(CMRE, 2019/06)In recent years, low-power high-frequency surface-wave radars have received significant attention thanks to their over-the-horizon coverage capability and the continuous-time operation mode. These radars have become effective ...