Results 201 to 210 of about 12,890 (241)

Deep ocean current profiling with a lowered broadband acoustic Doppler current profiler

Proceedings of OCEANS'94, 2002
An RD Instruments 150 kHz Broadband Acoustic Doppler Current Profiler (ADCP) has been mounted on a CTD frame and used to measure current velocity shear below the instrument during casts as deep as 5500 meters. By using processing techniques similar to those described by Firing and Gordon (1990) for a 300 kHz narrowband ADCP and Fischer and Visbeck ...
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Shipboard acoustic doppler current profiler surveys to assess tidal current resources

OCEANS 2010 MTS/IEEE SEATTLE, 2010
A compelling aspect of power generation from tidal currents is the predictability of the resource, which is generated by the gravitational pull of the sun and moon on the earth's oceans. For technical feasibility studies, it is presupposed that once the currents at a site have been well characterized it is possible to make accurate predictions of the ...
J Epler, B Polagye, J Thomson
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38 kHz broadband phased array acoustic Doppler current profiler

Proceedings of the IEEE Fifth Working Conference on Current Measurement, 2002
Recently RD Instruments (RDI) finished developing and demonstrating the performance of a prototype 38 kHz broadband phased array acoustic Doppler current profiler (ADCP) for deep ocean current measurement. Unlike conventional RDI ADCPs with four circular transducers, the prototype uses one flat face broadband phased array which is about the same size ...
null Xiaolong Yu, L. Gordon
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Measuring the Dispersion Coefficient with Acoustic Doppler Current Profilers

Journal of Hydraulic Engineering, 2007
A method is evaluated for estimating the longitudinal dispersion coefficient K from velocities and bathymetry measured with an acoustic Doppler current profiler (ADCP). If shear dispersion controls the mixing, the dispersion coefficient can be estimated from measurements of velocity and depth in a cross section. The dispersion coefficient has typically
Meredith L. Carr, Chris R. Rehmann
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Horizontal acoustic doppler current profile instrument development and applications

Proceedings of the IEEE/OES Seventh Working Conference on Current Measurement Technology, 2003., 2004
RD Instruments Inc, USA, (RDI) commercially developed the Broadband Acoustic Doppler Current Profiler (ADCP) in the early 1980s and has delivered more than 3500 instruments to over 50 countries, during the last 20 years. While vertical profiling from a fixed or moving platform is considered to be a standard application technique, horizontal profiling ...
N. Trenaman, R. Marsden
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Backscatter estimation using Broadband acoustic Doppler current profilers

Proceedings of the IEEE Sixth Working Conference on Current Measurement (Cat. No.99CH36331), 1999
Growing interest has developed in acoustic studies about the abundance and distributional patterns of the suspended matter, such as plankton and sediments, that act as sound scatterers for Broadband acoustic Doppler current profiler measurements. Supported by careful calibration procedures, acoustic studies using vertical profiles of echo intensity ...
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Acoustic doppler current profiling from a volunteer commercial ship

Proceedings of the 1986 IEEE Third Working Conference on Current Measurement, 2005
An acoustic Doppler current profiler has been successfully installed on a volunteer commercial ship, the 42,000 DWT oil tanker EXXON Jamestown, which makes monthly round trips from Houston, Texas to Santa Barbara, California via the Panama Canal. Doppler current data collected by the Jamestown so far indicate that the system noise levels are low and ...
D. Cutchin, J. Christensen, R. Knoop, J. Stillman, W. Woodward   +4 more
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A Towed Acoustic Doppler Current Profiler System.

1996
Abstract : This grant covered the cost of acquiring a complete towed ADCP/CTD system, assembling it and doing preliminary tests. The system has subsequently been used very successfully as part of the ONR-funded program 'A Towed Acoustic Doppler Current Profiler System,' to collect upper ocean profiles of current in the data scarce eastern Indonesian ...
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Results of a horizontally mounted acoustic Doppler current profiler

IEEE Oceanic Engineering Society. OCEANS'98. Conference Proceedings (Cat. No.98CH36259), 2002
Shallow, narrow and busy channels do not easily allow conventional current measurements in real time. The goal is to investigate the possibility of using data of a horizontally mounted ADCP for measuring flow velocity and direction in a river or channel.
S.D. Kamminga, N. van Neerven, C. Mooiman   +2 more
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Theoretical Accuracy of Doppler Navigation Sonars and Acoustic Doppler Current Profilers

IEEE Journal of Oceanic Engineering, 2004
This paper addresses the problem of Doppler shift estimation in Doppler sonar systems. The analysis focuses on the single-beam geometry formed by a circular planar array and considers both narrow-band (or so-called incoherent) and wide-band (or coherent) Doppler sonars, transmitting, respectively, one long continuous-wave pulse and a train of short ...
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