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A general purpose software system for applications in different fields of physics
(NATO. SACLANTCEN, 1979/12)
The paper presents the principle of a software system (FTSS) developed by the Danish Defence Research Establishment (DDRE) for applications in different fields of physics. Software is made up by independent modules exchanging ...
Evaluation of experimental techniques for determining the plane wave reflection coefficient at the sea floor
(NATO. SACLANTCEN, 1986/06)
One of the most commonly used techniques for determinati on of the geoacoustical properties of the sea bed is the measurement of plane wave reflection coefficients at the ocean bottom. An incident field is pr oduced by ...
A technique of comparative analysis of underwater sound transmission loss curves
(NATO. SACLANTCEN, 1975/10)
A procedure has been developed for the analysis of transmission loss curves in which received power is known or expressible as a linear function of range. The procedure separates each curve into a sum of three components ...
Relative contribution of surface roughness and bottom attenuation to propagation loss in shallow water
(NATO. SACLANTCEN, 1975/10)
A simulation study has been performed to investigate the relative importance of the contributions of surface roughness and bottom attenuation to propagation loss under differing environmental conditionso The NRL normal ...
Assessment techniques for computer models of sound propagation
(NATO. SACLANTCEN, 1975/10)
Computer models of sound propagation have exactly three drawbacks: the model only approximates reality,the computer program only approximates the model, and the cost approximates infinity. The only way to assess these ...
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 ...
Acoustic propagation models as viewed by the sonar systems designer
(NATO. SACLANTCEN, 1971/12)
The purpose of this paper is to consider the efforts performed in the development of ray acoustic propagation analyses from the viewpoint of advanced sonar system design. In particular, those parameters required of such ...
Numerical modelling of acoustic scattering by smooth inclusions in a layered fluid-solid medium
(NATO. SACLANTCEN, 1997)
A boundary integral equation (BIE) method as descnbed for computing the scattering of a monofrequent acoustic field by a smooth, rigid 30 object in a layered range-independent fluid-solid medium. The BIE is discretized ...
Critical angle and seabed scattering issues for active-sonar performance predictions in shallow water
(NATO. SACLANTCEN, 1997)
Active sonar performance predictions (0.75 to 3 kHz) are examined in summer shallow-water environments to quantify the impact of variable seabed and watermass properties on detection. Scattering is computed with an ...
A novel approach for a bistatic scattering calculation suitable for sonar performance model
(CMRE, 2014/01)
One of the classical approaches to the calculation of the sound pressure scattered from a rough surface is to sum the contributions to the field from a set of small tiles that approximate the surface. If the tiles are ...