Browsing by Type "Conference Proceedings (CP)"
Now showing items 201-220 of 314
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Physics of bottom scattering and some applications
(NATO. SACLANTCEN, 1997)The main bottom scattering theories are described in their bistatic formulation: composite-roughness, and volume scattering. Several applications are proposed. One of the main concerns is to check the mono- and bisfafic ... -
Position and shape of the surface shadow zone
(NATO. SACLANTCEN, 1971/12)From surface reverberation studies conducted by SACLANTCEN's Target Classification Group"C , it has been found necessary to know before any sea experiment the precise position of the first surface shadow zone. Since normal ... -
Practical active sonar receiver systems using fast frequency-domain correlation
(NATO. SACLANTCEN, 1993/08) -
Preliminary results of current measurements in the Strait of Sicily in May 1970
(NATO. SACLANTCEN, 1972/09)During May 1970, series of oceanographic observations were made in the Strait of Sicily in support of MILOCMED. Sections of hydrologic stations were made using temperature salinity recorder (TDS) and Nansen bottles by R/ ... -
Processing of broadband acoustic signals
(NATO. SACLANTCEN, 1972/05) -
Propeller leading edge trimming and maintenance effects on ship's noise operational performance
(NATO. SACLANTCEN, 1985/01)In the last ten years, considerable experience has been gathered at CEIMM's cavitation tunnel (Centra Esperienze Idrodinamiche Marina Militare) on the effects of propeller leading edge geometry on cavitation (and noise) ... -
Random temperature structure as a factor in long-range propagation
(NATO. SACLANTCEN, 1975/10)A statistical description of horizontal thermal microstructure in anosotropic turbulence is developed for application with an existing acoustic propagation theory. The model predicts a temperature power density spectrum ... -
Range-dependent normal modes in underwater sound propagation
(NATO. SACLANTCEN, 1975/10)Normal mode theory is best suited for the case of stratified media. Range dependence of the medium properties and of its boundary may nevertheless be taken into account in the framework of an adiabatic approximation provided ... -
Ray tracing on a mini-computer
(NATO. SACLANTCEN, 1971/12)It would appear that most people engaged in solving problems in ray- tracing, use programs written for large computers . These machines commonly have large memory sizes, fast cycle times and large word length 0 This paper ... -
Ray tracing on a mini-computer
(NATO. SACLANTCEN, 1972/05)It would appear that most people engaged in solving problems in ray- tracing, use programs written for large computers. These machines commonly have large memory si~es, fast cycle times and large word length . This paper ... -
Rays and statistical diffraction theory
(NATO. SACLANTCEN, 1971/12)A method of extending ray tracing is proposed, such that mediumscale irregularities of a statistical nature are taken into account along with large-scale irregularities in refractive index of the medium. -
Real time-frequency active sonar processing: a massively parallel approach
(NATO. SACLANTCEN, 1993/08)A paradigm for massively parallel processing of matched filters, replica correlators, ambiguity functions and time-frequency distributions using an SIMD (Single Instruction Multiple Data) programming methodology is presented. ... -
Real-time expanded-band beamforming using a complex heterodyner and fast array processor
(NATO. SACLANTCEN, 1979/12)At the Defense Research Establishment Atlantic Dartmouth, Nova Scotia, Canada a data aquisition sytem been engineered to monitor and beamform data from element line arrays. This system has been designed to with either towed ... -
Real-time processing of acoustic and oceanographic data at sea
(NATO. SACLANTCEN, 1972/05) -
Real-time, general-purpose, high-speed signal processing systems for underwater research: proceedings of a working-level conference held at SACLANTCEN on 18-21 September 1979 - part 1 : sessions 1 to 3
(NATO. SACLANTCEN, 1979/12)During the last few years, advances in the computer field have reached a level where it is possible to implement fast signal-processing systems through the use of standard computer equipment operating in association with ... -
Reflection of sound from a layered ocean bottom
(NATO. SACLANTCEN, 1975/10) -
Refraction of sound in the sea floor
(NATO. SACLANTCEN, 1975/10)A major mode of propagation of acoustic energy at low frequencies is a shallow refracted path through unconsolidated sediments of the sea floor. Successful modelling of the bottom-refracted mode of propagation requires ... -
Regional reflection seismic exploration of the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)A regional seismic reflection survey was performed by OGS in 1970 on the Sicily Channel, using multichannel digital techniques and flexotir source. Reflections up to about 5 s (two-way time) have been obtained. The analysis ...