Results 251 to 260 of about 196,454 (289)

Developments in acoustic sediment classification

IEEE Oceanic Engineering Society. OCEANS'98. Conference Proceedings (Cat. No.98CH36259), 2002
This paper describes several recent developments which improve the seafloor characterization and sediment classification capabilities of a state-of-the-art high resolution subbottom profiling system designated the Acoustic Seafloor Classification System (ASCS). The ASCS has been under development by the Naval Research Laboratory since 1993.
D.N. Lambert, D.J. Walter, D.C. Young, S.R. Griffin, K.C. Benjamin   +4 more
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Evolutionary Classification of Coastal Sediments

1991
ABSTRACT One of the most successful ways of classifying coastal environments has been to employ the dominant coastal process variables as discriminating parameters. This approach has been previously applied to deltas and continental shelves using the three parameters of waves, tides and rivers and to tidal inlets using only waves and ...
Ron Boyd, Robert Dalrymple, Brian Zaitlin   +2 more
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TEXTURAL CLASSIFICATION OF SEDIMENTS

Sedimentology, 1966
SUMMARYIn the light of present‐day requirements and the author's personal experience, existing systems of nomenclature and classification of sediments on a textural basis need revision. A system is proposed that is based on a three end‐member relationship involving sand‐, silt‐ and clay‐size particles.
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Recent advances in acoustic sediment classification

The Journal of the Acoustical Society of America, 1999
Most acoustic techniques used to classify seafloor sediments rely on operator experience and require extensive ground-truth data to calibrate system predictions. Recent developments in transducer design, inversion and deconvolution techniques, and sensor motion composition should improve the reliability and accuracy of normal-incidence, seafloor ...
Michael Richardson, Warren Wood, Wolfgang Jans, Peter Fleischer, Keven Briggs, Dawn Lavoie, Dan Lott, Doug Lambert, Dennis Lindwall, Don Walter, Sean Griffin, Eric Smith   +11 more
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Sediment Classification Using the Chirp Sonar

Offshore Technology Conference, 1992
ABSTRACT The chirp sonar is a quantitative seismic profiler used to generate high resolution reflection profiles of the seabed and estimates of the acoustic properties of sediments. Since the FM acoustic pulse is generated by a D/A converter with a wide dynamic range and a transmitter with highly linear components ...
S.G. Schock, L.A. LeBlanc, Satchidanarda Parda   +2 more
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Wavelet applications to bottom sediment classification

The Journal of the Acoustical Society of America, 1995
Wavelet signal decomposition techniques applied to fathometer echoes were used for seafloor classification. Fathometer echoes were deconvolved with their source signals to yield transfer functions representative of the seafloor. These transfer functions were then expanded onto damped complex exponential wavelet bases.
Russell Priebe, Nicholas P. Chotiros, Donald J. Walter, Douglas N. Lambert   +3 more
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Microstructural classification of clayey sediments

Geo-Marine Letters, 1991
Progress is being achieved in developing automatic methods of image analysis of electron micrographs for measuring the strength and direction of local preferred orientation, recognition of random areas, and measuring local variations in void ratio and other parameters.
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Sediment Classification by Seismic Reflectivity

OCEANS '76, 1976
A semi-automatic, electronic system used to measure seismic reflectivity of the water-bottom sediment is devised. The central part of the system is an apparatus designed to negate waveform spherical divergence using a linear ramp function coupled with a voltage multiplier circuit.
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Acoustic Sediment Classification Involving Gas-Laden Soils

Offshore Technology Conference, 1976
Abstract It has been demonstrated that acoustic echoes, returned from a multi-layered sea floor, are useful in identifying key properties of those sediments. The principal remotely measured classifiers in current use are sediment bulk density, intra-layer compressional wave velocity and attenuation rates.
Arthur S. Westneat, William S. Porter
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River Bed Sediment Classification Using ADCP

World Environmental and Water Resources Congress 2009, 2009
Description of physical aquatic habitat often includes data describing distributions of water depth, velocity and bed material type. Water depth and velocity in streams deeper than about 1 m may be continuously mapped using an acoustic Doppler current profiler from a moving boat.
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