Browsing Reprints by Type "Conference Proceedings (CP)"
Now showing items 81-100 of 290
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Comparison of measured reverberation on the transmission loss data with modelled results on the West Florida continental shelf
(NATO. SACLANTCEN, 1993/08)Acoustic data from the September, 1992 Area Characterization Test (ACT I) are compared to ADAM (Advanced Development Acoustic Model) output. Conduct of harsh shallow water acoustic exercises, and data interpretation mandates ... -
Comparison of propagation measurements obtained using the MEDUSA system with computer modelled data
(NATO. SACLANTCEN, 1971/12) -
Comparison of ray tracing predictions with wideband propagation measurements
(NATO. SACLANTCEN, 1971/12)The paper gives an illustration of the latest methods which have been developed at SACLANTCEN for the experimental study of sound propagation in deep water. They are based on a high sampling of the sound field produced by ... -
Computer models for underwater sound propagation
(NATO. SACLANTCEN, 1975/10)The state of affairs of computer models for underwater sound propagation loss estimation is discussed from the viewpoints of two segments of the sonar community; i.e., (1) those who develop the models and are primarily ... -
Connection between the solution of the Helmholtz and parabolic equations for sound propagation
(NATO. SACLANTCEN, 1975/10)Using a conformal mapping technique in a rectangular waveguide, we present an exact integral relation between the solutions of the Helmholtz equation whose sound speed c(x,y) varies as a function of both depth y and range ... -
Considerations on numerical and experimental propagation models for two-dimensional variations of medium properties
(NATO. SACLANTCEN, 1971/12)One of the problems the FWG is dealing with is the prediction of sound propagation loss in shallow water. A part of this problem is being treated by bringing measurements and numerical computation into relationship. -
Considerations related to warfare system design and operation of tactical platforms in a low- frequency active sonar environment
(NATO. SACLANTCEN, 1993/08)Low-Frequency Active Sonar System (LFASS) can provide significant improvements in the detection, localization and classification of very quiet submarine contacts. Achievement of the predicted performance improvements will ... -
Considerations relating to the calculation of sound velocity
(NATO. SACLANTCEN, 1971/12) -
Continuous recording of active sonar data
(NATO. SACLANTCEN, 1972/05) -
Correlation of backscatter with bottom topography
(NATO. SACLANTCEN, 1993/08)Practical data from low frequency sonar operations in shallow water has been analysed to demonstrate that a high degree of correlation exists between the received signal due to bottom hackscattering and the hottom gradient ... -
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 ... -
Depth dependence of directionality of ambient noise in the North Pacific: experimental data and equipment design
(NATO. SACLANTCEN, 1982/06)Ambient ocean noise studies have been part of the research program of the Marine Physical Lab (MPL) for many years. In recent years this work has included several studies of the depth dependence of vertical directionality ... -
Detection models and target information processing
(NATO. SACLANTCEN, 1982/06)The passive sonar equation leads in a natural manner to sensor detection performance contours. Useful information can be extracted from observed fractional holding time on non-cooperative targets by use of these contours. ... -
Determination of velocity profile and sea bed characteristics from high frequency pulse propagation in a shallow water Mediterranean environment
(NATO. SACLANTCEN, 1997)Time-domain features of shallow water Mediterranean and Yellow Sea data are simulated for frequency band widths of 0.8 kHz with a centralfrequency of 3.2 kHz. Contour plots of pulse arrivals in time and depth are analyzed ... -
Deterministic methods of sound field computation
(NATO. SACLANTCEN, 1975/10)Models for acoustic propagation in the ocean environment have matured to a level where they are used routinely to estimate deterministic phenomena and, most recently, have been applied to the investigation of stochastic ... -
Development of military ARGUS computers and MOD bus for close-coupled signal processing applications
(NATO. SACLANTCEN, 1979/12)The next generation of Naval sonar systems will make extensive use of flexible programable modules to implement signal-processing algorithms. A number of UK Defence Establishments are engaged in a series of coordinated ... -
Different approaches to economic cruising speeds on a CODOG frigate with due regard to radiated noise
(NATO. SACLANTCEN, 1985/01)All navies, in recent years, have been much more concerned in economic cruising speeds of ships. Frigate type naval ships are usually characterized by two shafts, by multiple propulsion engines per shaft, and by different ... -
Digital acoustical processing at Woods Hole Oceanographic Institution
(NATO. SACLANTCEN, 1972/05) -
Digital signal processing of high resolution within-pulse sector scanning sonars
(NATO. SACLANTCEN, 1979/12)The characteristics of three scanning sonars, presently in use at the Admiralty Marine Technology Establishment, and operating at frequencies of 300kHz, 150kHz and 75kHz are described. The performance of a system for ...