| The New Age of Scientific Partnerships: Acoustic Capabilities and Facilities at NUWC Division, Newport -- Surface ASW Directorate Outlook |
29 SEP 94 |
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| Authors:
Peter D. Herstein; Joseph M. Monti; David G. Browning; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
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| NUWC Shallow Water Curtain Effect with Biot Bottom Loss: System Impact |
25 OCT 93 |
14 pages |
| Authors:
David G. Browning; Raymond J. Christian; Peter D. Herstein; Joseph M. Monti; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV NEW LONDON CT NEW LONDON DETACHMENT
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 | The Curtain Effect was originally conceived to compare the relative rates of loss of spreading and attenuation in deep water in order to estimate possible attainable acoustic detection ranges. It was later modified to compare spreading, attenuation, and bottom loss in shallow water for the same purpose (NUWC-NL Technical Document 4009, 2 March 1992). We now compare the Shallow Water Curtain under strongly downward refracting conditions for various source/ receiver ... |
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| A Survey of the Impact on Acoustic Propagation of Warm Core Ocean Eddys |
21 SEP 93 |
22 pages |
| Authors:
David G. Browning; Joseph M. Monti; Linda S. Petitpas; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
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| Warm core eddys have been found throughout the oceans of the world. Most have a bowl-like shape extending down from the surface, which, along with an increased sound speed due to the warmer water core, causes more acoustic energy to be refracted toward the surface than would occur without an eddy present. However, the impact on acoustic propagation varies significantly from ocean to ocean, because of variations in eddy size ... |
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| A Study of Low Frequency Sound Propagation in Shallow Water Ducts |
14 FEB 92 |
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| Authors:
Joseph M. Monti; Jeffrey H. Sammis; David G. Browning; Peter D. Herstein; NAVAL UNDERSEA WARFARE CENTER NEW LONDON CT NEW LONDON DETACHMENT
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 | This paper presents results from a recent investigation of shallow water propagation loss for low frequencies (500-4000 Hz). Shallow water is defined in this context as a location where acoustic energy has numerous boundary interactions. This definition leads to both physically shallow and not- so-shallow sites. The objectives of this investigation are, first, to gain a quantitative understanding of propagation loss as a function of source/receiver placement and frequency for ... |
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| A Comparison of Parabolic Equation Models with a Stepwise Coupled Modes Model |
31 MAR 88 |
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| Authors:
Joseph M. Monti; James Syck; NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT NEW LONDON LAB
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| Parabolic equation calculations are compared with stepwise coupled mode, COUPLE, calculations for a set of runs for which the two models have overlapping capability. The PE calculations were then extended to consider the additional case of refracting sediment. Normal mode start up fields were used in the calculations. PE models have capabilities differing in the areas of wide angle capability, treatment of the ocean bottom and numerical methods. The intent ... |
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| The Influence of Surface Roughness and Bubbles on Sea Surface Acoustic Backscattering (Der Einfluss von Seegangsrauhigkeit und Blasen auf die Akustischen Rueckstreueigen-Schaften der Meeresoberflaeche) |
12 NOV 1987 |
61 pages |
| Authors:
Bernd Neutzel; Heinz Herwig; Joseph M. Monti; Paul D. Koenigs; FORSCHUNGSANSTALT DER BUNDESWEHR FUER WASSERSHALL- UND GEOPHYSIK KIEL (GERMANY F R)
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| The results from a recent sea surface acoustic scattering experiment, which was conducted in the North Sea, are presented with accompanying sea surface roughness parameters and subsurface bubble information. The acoustic data were obtained utilizing a high-resolution (narrow beamwidth) pulsed parametric sonar transmitter and conventional receiver. Scattering strength values were obtained as a function of frequency (3-18 kHz) and grazing angle (15 to 90) for differing sea surface roughness and ... |
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| The Influence of Bubbles on Sea Surface Backscatter Measurements (Der Einfluss von Blasen auf die Messung der Rueckstreueigenschaften der Meeresoberflaeche) |
26 OCT 86 |
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| Authors:
Paul D. Koenigs; Joseph M. Monti; Bernd Nuetzel; Heinz Herwig; NAVAL UNDERWATER SYSTEMS CENTER NEWPORT RI
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| Results from a recent sea surface acoustic scattering experiment, conducted in the North Sea, are presented with accompanying sea surface roughness parameters and subsurface bubble information. The acoustic data were obtained using a high resolution (narrow beamwidth) pulsed parametric sonar transmitter and conventional receiver. Scattering strength values were obtained as a function of frequency (3-18 kHz) for wind speeds from 2 to 45 knots. It appears that the backscattering strength ... |
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| Effects of Acoustic Multipath Interactions on Source Range and Bearing Estimation for a Focused Line Array |
24 MAY 85 |
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| Authors:
Joseph M. Monti; Paul D. Koenigs; NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT NEW LONDON LAB
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| A computer simulation technique was developed to investigate the effects of acoustic multipath interactions on source range and bearing estimation for a focused line array. To simulate the multipath environment, the Generic Sonar Model (Weinberg, NUSC TD 5971, 19 December 1981) was used to modify source signals and emulate oceanic transmissions to individual sensors. Characteristics of a narrowband frequency domain focused beamformer were implemented incorporating wavefront curvature techniques and a ... |
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