Browsing by Title
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Sensitivity of ray theory to input data
(NATO. SACLANTCEN, 1971/12)Acoustic propagation problems which are solved using ray theory require certain input data. In particular, the source and receiver locations, sound-velocity field and bottom and surface conditions are required. Frequently, ... -
Sensor-driven glider data processing
(CMRE, 2019/06)Gliders data are an important source of observations for oceanographers, hence harmonization and interoperability among different acquisition systems are key enablers towards efficient data sharing and effective reuse. As ... -
Separability of scattering and reflection parameters in reverberation inversion
(NURC, 2007/11)A premise of reverberation inversion is that one can separate geoacoustic reflection properties from scattering properties since their effects on reverberation are distinguishable. Some doubt has been cast on this premise ... -
Separability of seabed reflection and scattering properties in reverberation inversion
(NURC, 2007/02)Separation of scattering properties (Lambert's mu) from reflection properties (the reflection loss angle derivative alpha) presents difficulties in the geoacoustic inversion of long range reverberation in isovelocity ... -
Separation of measured noise coherence matrix into Toeplitz and Hankel parts
(CMRE, 2017/08)The cross-spectral density of ocean ambient noise is usually estimated from the product of the complex hydrophone signals, each of which already corresponds to the summed responses of sources from all angles. The true ... -
Shallow seafloor geology and sediment character ofthe western Mallorca Platform
(NATO. SACLANTCEN, 1995/03)A site survey of the seabottom west of Mallorca in the central Balearic Islands has characterized the bottom and the immediate sub-bottom. High resolution seismic reflection Uniboom, deeper penetrating (about 5x Uniboom) ... -
Shallow water propagation incorporating both bubble plumes and sea-surface roughness
(NATO. SACLANTCEN, 1997)The effect of including a range dependent bubble layer and a suitable sea surface spectrum in modeling shallow water propagation is analyzed. Propagation is simulated through a hrghly accurate model based on a modified PE ... -
Shallow water reverberation modeling using an autoregressive range-scattering function approach
(NATO. SACLANTCEN, 1997)The primary limitation on system performance for active sonars is reverberation - the reradiation of acoustic energy back to the receiver from inhomogeneities in the physical properties of the medium and its boundaries. A ... -
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 ...