Browsing CMRE Publications by Title
Now showing items 703-722 of 882
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Shallow water synthetic aperture sonar: an enabling technology for NATO MCM forces
(NURC, 2007/10)The change in military focus from Cold War doctrine to expeditionary operations in shallower littoral water and the heightened terrorist threat to ports and their approaches, have put increased emphasis on countering ... -
Shallow-water ASW sonar design
(NATO. SACLANTCEN, 1993/08) -
Shallow-water coherence of broadband signals
(NATO. SACLANTCEN, 1997)The frequency-dependent spatial and temporal variabilities of sound propagation in coastal regions is investigated by ezperiment and numerical simulations. Experimental observations show that temporal coherence of the ... -
Shallow-water seafloor characterization for high-frequency multibeam echosounder: image segmentation using angular backscatter
(NATO. SACLANTCEN, 1997)Sonar images from multibeam echosounders are submitted to various degradations, partly due to the sensor itself: Signal artefacts and corresponding corrections are presented, both for signal processing and for array ... -
Shallow-water sound transmission measurements taken on the New Jersey continental shelf
(NATO. SACLANTCEN, 1993/08)Calibrated acoustic measurements were made under calm sea state conditions on the New Jersey shelf near the AMCOR 6010 borehole, a surveyed area with known geophysical properties. The experiment was conducted in 73 m water ... -
Shear properties of ocean sediments determined from numerical modelling of Scholte wave data
(NATO. SACLANTCEN, 1986/06)Recently it has become apparent that shear properties of ocean sediments are most easily determined from measured propagation characteristics of seismic interface waves. We use a newly developed numeri ca l model of wave ... -
Short-period vertical displacements of the upper layers in the Strait of Gibraltar: part 1 - text: part 2 - diagrams
(NATO. SACLANTCEN, 1964/11)The report is principally based on observations of short-term displacements made by the author in the summers of 1958, 1959, and 1961, using a thermistor chain. Pilot tubes installed on the thermistor chain made simultaneous ... -
Signal and reverberation formulae including refraction
(NATO. SACLANTCEN, 2003/04)Because reverberation is an incoherent process it is possible to base realistic solutions on very simple flux theory. This report extends the closed-form signal and reverberation formulae of an earlier report [SACLANTCEN ... -
Signal processing for an active sonar system suitable for advanced sensor technology applications and environmental adaptation schemes
(NURC, 2006/08)An overview of the basic elements of an active sonar system in conjunction with a description of the signal processing chain utilized at the NATO Undersea Research Centre for detection and localization of undersea targets ... -
Signal-processing language and operating system
(NATO. SACLANTCEN, 1979/12)Signal Processing Language/One (SPL/I) was developed at the Naval Research Laboratory (NRL) as a high-level computer programming language for signal processing. SPL/I is the first high-level language to be designed for ... -
Silent ship research applications and operation: proceedings of a conference held at SACLANTCEN on 2-4 October 1984 - volume 2: unclassified papers
(NATO. SACLANTCEN, 1985/01)Introduction: The project to construct an acoustically quiet research ship for the SACLANT ASW Research Centre provided a reason for SACLANTCEN to organize a conference on silent ships, their operation and applications. ... -
Simple instrumentation for measuring temperature gradients at the sea-air interface, including the results of Winter 1964/65 measurements
(NATO. SACLANTCEN, 1965/07)Very little information is available on the temperature differences in the first several centimetres of air above the sea surface and the first few centimetres of water below the sea surface. Data of this kind are important ... -
Simultaneous analysis in real time
(NATO. SACLANTCEN, 1972/05) -
Single mode excitation, attenuation and backscatter in shallow water
(NATO. SACLANTCEN, 1995/10)Normal mode theory is used to illustrate that a vertical array of weighted sources driven in an -
Single ping clutter reduction: segmentation using Markov random fields
(NATO. SACLANTCEN, 1999/03)The use of low frequency active sonar in shallow water leads to large numbers of clutter detections. This high false alarm rate can overload automatic tracking and classification algorithms. Traditional detection algorithms ... -
Site and frequency dependence of ambient noise in the North Eastern Pacific Ocean
(NATO. SACLANTCEN, 1982/06)One-hour averages of omnidirectional ambient noise measurements at 60 Hz and 165 Hz are analyzed for two nearby, deep ocean sites in the Northeastern Pacific during February and March 1981. Site A is a high noise site and ... -
Site dependence of wind-dominated ambient noise in shallow water
(NATO. SACLANTCEN, 1982/06)A survey of ambient noise data in shallow water taken under wind-dominated conditions shows substantial differences in spectrum level (often greater than 10 dB) under the same windspeerl and sea-state conditions. This ... -
Small scale volumetric inhomogeneities of shallow water sediments: measurements and discussion
(NATO. SACLANTCEN, 1997)There is a consensus that high-frequency acoustic scattering by the ocean bottom is partly due to sediment volumetric inhomogeneities, r e., random fluctuations in sediment sound speed and density. Understanding the spatial ... -
Some acoustic effects of internal macrostructure
(NATO. SACLANTCEN, 1975/10)Some recent experimental developments relating to internal oceanographic- acoustic interactions are reviewed. Besides amplitude and phase fluctuations, a major concern is scattering into shadow regions. Associated oceanographic ... -
Some acoustical characteristics of underwater explosions of hydrogen-oxygen mixtures
(NATO. SACLANTCEN, 1963/02)The acoustic characteristics of a hydrogen-oxygen explosive mixture are investigated in an attempt to find a substitute for solid explosives (e.g. TNT) which will achieve a simple underwater acoustic pulse uncomplicated ...