Browsing CMRE Publications by Subject "Mine burial and bottom conditions"
Now showing items 1-14 of 14
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A method for the three-dimensional reconstruction of underwater objects
(NATO. SACLANTCEN, 1996/10)This report describes a method to estimate the three-dimensional aspects of underwater objects using a sequence of sonar images. The data are recorded by a sector scanning sonar, carried by an underwater vehicle which ... -
A parametric synthetic aperure sonar for detection of proud and buried mines
(NATO. SACLANTCEN, 1997/12)This paper describes an experimental comparison between a parametric sonar and a conventional sonar for the detection of small objects on and in, the sea bed. Two experiments were performed in France (GESMA site) in October ... -
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 ... -
Characteristics of the mediterranean seagrass Posidonia oceanica contributing to high-frequency acoustic scattering
(NATO. SACLANTCEN, 2000/05)Posidonia oceanica meadows are the most important ecosystem for the life cycle of coastal Mediterranean benthos with a fundamental role in the primary production of the neritic system and a decisive influence on other ... -
Detection of buried mines using Rayleigh-scattered second-derivative Gaussian pulses
(NATO. SACLANTCEN, 1995/10)Large ground mines which are intentionally or unintentionally buried in the sediment have proven to -
Generic Oceanographic Array Technologies (GOATS)'98: bi-static seabed scattering measurements using autonomous underwater vehicles
(NATO. SACLANTCEN, 1998/10)The GOATS'98 experiment was performed May 5-29, 1998 in shallow water off Marciana Marina, on the island of Elba, Italy. The experiment addressed some of the fundamental issues associated with using the new Autonomous Ocean ... -
Measurements of acoustic scattering from partially and completely buried spherical shells
(NATO. SACLANTCEN, 1999/04)Recent work at NATO SACLANT Undersea Research Centre has concentrated on investigating the use of low frequency sonars (2-20 kHz) in order to better exploit scattering features of buried targets that can contribute to their ... -
Mechanisms for subcritical penetration into a sandy bottom: experimental and modelling results
(NATO. SACLANTCEN, 1998/05)This paper presents the results of a recent study whose overall objectives are to determine the mechanism(s) contributing to subcritical acoustic penetration into ocean sediments, and to quantify the results for use in ... -
Modeling of subcritical penetration into sediments due to interface roughness
(NATO. SACLANTCEN, 1997)Recent experimental results reveal acoustic penetration into sandy sediments at grazing angles below the critical angle. We have been investigating a mechanism for subcritical penetration based on scattering at a rough ... -
Modelling of scattering by partially buried elastic cylinders
(NATO. SACLANTCEN, 1998/02)The work of a previous memorandum on the modelling of scattering by a partially buried cylinder is extended to allow the cylinder to have full elasticity (and not just be a fluid structure as in the previous work). The ... -
Modelling scattering from partially buried cylinders = Acoustic scattering from cylindrical objects embedded between two half-spaces/The computation of the scattered pressure field from a cylinder embedded between two half-spaces = The computation of the scattered pressure field from a cylinder embedded between two half-spaces with different densities
(NATO. SACLANTCEN, 1996/12)1. A boundary integral equation method is presented for the computation of the acoustic field scattered from a cylindrical object which is totally within the water column, totally buried in sediment, or partially buried. ... -
Penetration of acoustic waves into sandy seafloors at low grazing angles: the Helmholtz-Kirchhoff approach
(NATO. SACLANTCEN, 1998/08)The Helmholtz-Kirchhoff integral is applied to model the penetration of sound waves into sandy seafloors at grazing angles above and below the critical angle. Although the conditions for the validity -
Physics of 3-D scattering from rippled seabeds and buried targets in shallow water
(NATO. SACLANTCEN, 1998/05)The new OASES-3D code developed at MIT is used to investigate the spatial and temporal characteristics of reverberation from rippled seabeds insonified by narrow beam sonars such as the TOPAS parametric source. It is shown ... -
Scattering from an elastic cylinder buried beneath a rough water/sediment interface
(NATO. SACLANTCEN, 1997)In this paper a plane-wave decomposition method is used to compute the two-dimensional backscattering from a buried elastic cylinder as a function of frequency. The cases of a pat water/sediment interface and deteministically ...