Reprints: Recent submissions
Now showing items 361-380 of 548
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The effect of water column stability on acoustic backscatter from the ocean bubble layer
(NATO. SACLANTCEN, 1997) -
Time-frequency representation of model based high frequency broad band scattering from a rough interface
(NATO. SACLANTCEN, 1997)A formulism for scattering a broad band high frequency pulse from a randomly rough surface of n penetrable oceanic sediment is developed and used to investiyate the ability of local cosine transform (LCT) rime-frequency ... -
Multipath field representation for seabed parameter extraction using backscatter data from shadow zones
(NATO. SACLANTCEN, 1997)Inversion strategies for bottom parameter estimation in shallow water impose stringent requirements on accuracy and speed of acoustic models. We highlight the importance of second order effects as first order determinants ... -
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 ... -
High frequency acoustic propagation in coastal waters
(NATO. SACLANTCEN, 1997)High Frequency Acoustic Propagation experiments were performed with bottom-mounted sources and receivers at different coastal sites. A measurement technique has been developed and propagation loss data have been taken using ... -
A survey of practical considerations relative to the processing and analysis of underwater acoustic signals
(NATO. SACLANTCEN, 1972/05)An investigation, aimed at bringing into sharper focus · tb~ strong interrelationships that exist between the measurement, p r o c essing, and analysis of underwater acoustic signals, is conducted. Emphasis is on practical ... -
Processing of broadband acoustic signals
(NATO. SACLANTCEN, 1972/05) -
Tactical data acquisition experiences
(NATO. SACLANTCEN, 1972/05)The requirements of Tactical Data Acquisition systems are discussed and summarized. Experiences with equipment and their utilization are described including : quantities measured, input signal conditioning, analogue ... -
A direct digital acquisition system
(NATO. SACLANTCEN, 1972/05) -
Simultaneous analysis in real time
(NATO. SACLANTCEN, 1972/05) -
Continuous recording of active sonar data
(NATO. SACLANTCEN, 1972/05) -
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 ... -
Magnetic, gravity and depth surveys in the Mediterranean and Red Sea
(NATO. SACLANTCEN, 1965/04)This report is a copy of a paper published in Nature, Vol. 204, 4965, 1964: 1245-1248 by T.D. Allan of this Centre, H. Charnock of this Centre at the time of the surveys but now of the National Institute of Oceanography, ... -
The ARL shipborne computer system
(NATO. SACLANTCEN, 1972/05) -
Numerical modeling results for mode propagation in a wedge
(NATO. SACLANTCEN, 1987/11)A PE (parabolic equation) code is used to study propagation in a shallow water wedge with a penetrable bottom. Particular attention is given to "wedge modes" that have wave fronts that are arcs of circles centered on the ... -
Subcritical penetration of narrow Gaussian beams into sediments
(NATO. SACLANTCEN, 1988/03)Complete wave-theory solutions have been obtained numerically for both the reflected and the transmitted fields associated with a narrow Gaussian beam incident on a water-sediment interface near the critical grazing angle. ... -
Summary and recommendations
(NATO. SACLANTCEN, 1971/12)An unfortunate first impression might be that ray tracing is dull, simply because the idea is a very old one. In fact, ray tracing is the single most powerful method available to us for understanding the complexities of ... -
Acoustic propagation through oceanic fronts
(NATO. SACLANTCEN, 1971/12)A resume was given of recent experiments in the Mediterranean, East of Malta, designed as a preliminary test of the effect of oceanic fronts on acoustic propagation. It was apparent that in certain circumstances the ... -
Oceanic-acoustic experiments at SACLANTCEN
(NATO. SACLANTCEN, 1971/12)Last year, at the Director's suggestion, a project in oceanicacoustics was set up at the Centre with scientists from at least 3 groups playing some part in the planning and execution of experiments. The p roject represents ...