Browsing by Title
Now showing items 188-207 of 882
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Beam spreading and loss of spatial coherence in an inhomogeneous and fluctuating ocean
(NATO. SACLANTCEN, 1975/10)A theory has been developed that enables estimates to be made of beam bending, beam spreading and loss of spatial coherence. In this paper we concentrate on the loss of spatial coherence due to scattering. Using a minus ... -
Belief propagation based AIS/radar data fusion for multi-target tracking
(CMRE, 2019/05)A data fusion technique aiming at combining observations from two classes of sensors is proposed. The first class consists of sensors that produce periodic noisy observations of the targets; moreover, they may also miss ... -
Benchmark analysis of NURC multistatic tracking capability
(NURC, 2006/08)This paper provides a brief description and performance results for the multistatic sonar trackers developed at NURC. Our analysis is based on common data distributed as part of the Multistatic Tracking Working Group ... -
Benchmark evaluation of multistatic trackers
(NURC, 2006/08)This paper provides an overview of the Special Session on Multistatic Sonar and Radar Tracking at FUSION 2006. This includes background on the Multistatic Tracking Working Group, a brief description of the datasets and ... -
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