Browsing by Title
Now showing items 192-211 of 882
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Benchmarking of SCARAB volume scattering versus OASES volume scattering
(NATO. SACLANTCEN, 2001/05)OASES uses wavenumber integration to solve for the backscattered pressure caused by sound speed and density inhomogeneity scatterers in the sediment; SCARAB uses a ray path technique to find the backscattered intensity. ... -
Benchmarking scattering in ocean waveguides
(NATO. SACLANTCEN, 1995/07)Accurate numerical solutions are presented for benchmark problems -
Benefit assessment of glider adaptive sampling in the Ligurian Sea
(CMRE, 2014/01)The benefits of piloting a glider during a 6-day period via an adaptive sampling procedure in a 80 × 60 km2 marine area are assessed under a fully operational framework. The glider trajectory was adapted to reduce the ocean ... -
Bibliography electromagnetic phenomena with special reference to ELF (1-300 cps)
(NATO. SACLANTCEN, 1964/10)Contents: Propagation of EM Waves, Surface Waves, Ionosphere; Calculation of DC and EM Fields, Antennas; Analysis, Measuring Methods, Magnetometers, Correlation; Geomagnetic Fluctuations, Solar Activity, Earth Currents; ... -
Bispectrum of ship-radiated noise
(NATO. SACLANTCEN, 1988/07)The bispectrum of ship radiated noise is estimated. The noise was received on a towed array being towed by the same ship that served as the noise source. The array was beamformed such that the forward endfire beam pointed ... -
Boosting the talent of new generations of marine engineers through robotics competitions in realistic environments: the SAUC-E and euRathlon experience
(CMRE, 2019/06)This article summarizes the experience of the NATO Science and Technology Organization (STO) Centre for Maritime Research and Experimentation (CMRE) in the organization of the Student Autonomous Underwater Vehicle ... -
Bottom bistatic scattering: experimental results and model comparison for a carbonate sediment
(NATO. SACLANTCEN, 1997)Bistatic scattering measurements were carried out under the Coastal Benthic Boundary Layer (CBBL) program. The results presented here are for a carbonate sand-silt-clay, and the data were collected in Februar) 1995 near ... -
Bottom reflection properties deduced from an ambient noise: simulation of a processing technique
(NATO. SACLANTCEN, 2002/11)A promising new method has already been proposed [SACLANTCEN SM-387] to calculate bottom reflection loss from ambient noise directionality. Although this method has been tried experimentally at more than 11 sites under ... -
Bottom reverberation in shallow water: coherent properties as a function of bandwidth, waveguide characteristics and scatterer distribution
(NATO. SACLANTCEN, 1998/10)Scattering physics are often modeled using the Helmholtz equation for computational reasons. Likewise, propagation loss to and from scattering regions are often treated in a like manner. The usual approach for generating ... -
Bottom scattering measurements in shallow water
(NATO. SACLANTCEN, 1999/08)Sonar performance predictions of reverberation in shallow water rely upon good estimates of the bottom scattering strength. However, little is understood about bottom scattering in shallow water in -
Bottom time spread and bistatic scattering by rough basalt
(NATO. SACLANTCEN, 1993/08)Scattering from oceanic basalt affects low-frequency active sonar systems in at least two important ways: (1) Significant time, angle and frequency spreading reduces target echo levels when systems over-resolve the spread; ... -
Bottom-interacting ocean acoustics: proceedings of a conference held at SACLANTCEN on 9-13 June 1980
(NATO. SACLANTCEN, 1980/07) -
Bottom/subbottom surveying using a new, parametric, sidescan sonar
(NATO. SACLANTCEN, 1997)The Naval Research Laboratory (NRL) has developed a dual-frequency, towed, interferometric, sidescan sonar system known as the Subbottom Swath System, which is capable of detecting objects and structures buried below the ... -
Broad-band geoacoustic inversion in shallow water from waveguide response measurements on a single hydrophone: theory and YELLOW SHARK experimental results
(NATO. SACLANTCEN, 1999/05)Executive summary: Performance models such as the Allied Environmental Support System (AESS) require environmental input parameters such as the geoacoustic properties of the battlespace. The models ingest the input parameters ... -
Broadband acoustic transmission intensity fluctuations in the Tyrrhenian Sea
(NATO. SACLANTCEN, 1996/11)An acoustic propagation experiment was carried out in the Tyrrhenian Sea in October 1985 in which signals from a broadband source were recorded at a range of 5 km with a vertical 62 m hydrophone array over a period of 5 ... -
Broadband geo-acoustic inversion from sparse data using genetic algorithms: results from the 1997 Geo-Acoustic Inversion Workshop
(NATO. SACLANTCEN, 1998/03)Matched field acoustic inversion techniques were investigated -
Broadband signal simulation in shallow water
(NATO. SACLANTCEN, 2002/12)Today's minimum requirements for ocean acoustic models are to be able to simulate broadband signal transmissions in 2D varying environments with an acceptable computational effort. Standard -
C-SNAP: Coupled SACLANTCEN Normal mode propagation loss model
(NATO. SACLANTCEN, 1993/12)On the basis of a widely used and efficient range-independent normal mode code, SNAP, and a numerical solution technique for one-way mode coupling obtained from KRAKEN, we have built a range-dependent propagation loss model ... -
Calculation of propagation losses in a medium with a velocity profile approximated by a number of Epstein profiles
(NATO. SACLANTCEN, 1971/12)This paper presents a digital ray-theory program, by which the ray trace, travel time and intensity can be calculated for velocity profiles approximated by a number of Epstein functions. -
Calculation of reverberation and average intensity of broadband acoustic signals in the ocean by means of the RAIBAC computer model
(NATO. SACLANTCEN, 1976/04)Based on the conventional ray-tracing principle, a fast numerical algorithm is developed that calculates averaged propagation loss and reverberation of underwater sound. The averaging is performed by summing incoherently ...