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IEEE Journal of Oceanic Engineering

Issue 4 • Oct 1991

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Displaying Results 1 - 19 of 19
  • Acoustic Doppler current profiler performance in near surface and bottom boundaries

    Publication Year: 1991, Page(s):390 - 396
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (528 KB)

    The authors discuss the current measurement accuracy of the RD Instruments 1200-kHz acoustic Doppler current profiler (ADCP) in the near surface and bottom boundaries. Data are presented from tests. In the first series of tests, an ADCP was mounted on a bottom sled in an upward looking mode. The sled was towed at known speeds with and without surface waves. Additionally, tests were conducted with ... View full abstract»

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  • A current meter with intelligent data system, environmental sensors, and data telemetry

    Publication Year: 1991, Page(s):319 - 328
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (984 KB)

    To measure oceanographic parameters such as currents, temperature, conductivity, pressure, and suspended sediment concentrations, two film-recording current meters were upgraded with microprocessor-controlled data recorders and additional sensors. Two telemetry links relay data and allow the in situ operation of the remote instrument to be checked. In one configuration, the bottom-mounted current ... View full abstract»

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  • Optoelectronic system for the measurements of ship models trajectory

    Publication Year: 1991, Page(s):434 - 437
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    When using self-propelled ship models, it is necessary to observe and record a trajectory of actual movement and also to determine a current value of velocity and acceleration. An optoelectronic system for determining and recording the trajectory of the model has been developed. It operates over an 150 m×150 m area with a fundamental error of less than 0.1 m and consists of an optical transm... View full abstract»

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  • Accurate current measurement using drogued buoys employing Decca Navigator and Argos

    Publication Year: 1991, Page(s):307 - 312
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    Free-floating drogued buoys have been developed for detailed studies of tidal processes, frontal circulation, eddies, and mixing in the North Sea. They are equipped with two independent tracking systems-Decca Navigator and Argos. Decca Navigator, a hyperbolic radio navigation system with extensive coverage in Western Europe, provides accurate and frequent fixes, and the Argos satellite system is u... View full abstract»

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  • Single ping ADCP data

    Publication Year: 1991, Page(s):382 - 389
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    Because acoustic Doppler current profiler (ADCP) data are inherently noisy, they are usually presented in an averaged form. But a great deal can be learned, particularly about the ADCP system itself, by looking at single ping data. The author presents examples of analyses done on single ping data and shows how these data can be used to understand system sampling, bin-to-bin independence, system no... View full abstract»

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  • Acoustic Doppler current meter

    Publication Year: 1991, Page(s):420 - 426
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    A current meter designed to measure velocity profiles in the water column above the bed is described. The solution proposed is a coherent backscatter Doppler sonar system using a single transducer. A range-velocity product of 20 m2/s can be achieved by combining state of the art sonar techniques with new processing methods and careful, highly flexible design. Large range-velocity produc... View full abstract»

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  • High-speed real-time data acquisition for vector measuring current meters

    Publication Year: 1991, Page(s):360 - 367
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (804 KB)

    The authors describe an integrated hardware and software approach used to provide real-time acquisition and display of vector measuring current meter (VMCM) data at high sample rates (0.5 Hz) with supporting data from other instruments of somewhat slower rates. The hardware component consisted of a new circuit board for the VMCM that captured the VMCM data output, stored it, and transmitted it at ... View full abstract»

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  • Design and tests of a trawl-resistant package for an acoustic Doppler current profiler

    Publication Year: 1991, Page(s):397 - 401
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (592 KB)

    A package designed to protect an RD Instrument Ltd. acoustic Doppler current profiler survived several passages of a bottom trawl. The package, in the shape of a truncated pyramid, has a base 4 m by 3.3 m and a height of 53 cm. The authors describe the package, its deployment method, and field test results where a trawl was repeatedly dragged over the unit. The device has been used successfully th... View full abstract»

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  • Error analysis of an acoustic current meter

    Publication Year: 1991, Page(s):329 - 337
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (696 KB)

    Accuracies of the benthic acoustic stress sensor (BASS) and the proposed modular acoustic velocity sensor (MAVS) are evaluated. A simple model of the hydrodynamic sources of error for acoustic current meters is presented and compared with the measured performance of BASS in a tow-tank and in field deployments. The sources of error addressed include those due to ideal flow around the sensor cage, w... View full abstract»

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  • Transport measurements from in-service undersea telephone cables

    Publication Year: 1991, Page(s):313 - 318
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    The motion of the ocean through the Earth's magnetic field creates a cross-stream voltage proportional to the transport of the stream. These motion-induced voltages have been observed for more than ten years by the use of an abandoned cable spanning the Florida Current. In-service undersea telephone cables, including fiber optic cables with branch lines, can also be used to determine the motion-in... View full abstract»

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  • Directional ocean wave spectra using buoy azimuth, pitch, and roll derived from magnetic field components

    Publication Year: 1991, Page(s):427 - 433
    Cited by:  Papers (9)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    Buoy azimuth, pitch, and roll, when used with measurements of buoy vertical acceleration, can provide directional wave spectra. Earlier work, which considered effects of buoy hull magnetism, showed that azimuth can be determined from magnetic field measurements (K.E. Steele and J.C. Lau, 1986). This work is extended to show that buoy pitch and roll, and thus buoy slopes, can also be determined fro... View full abstract»

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  • A note on the use of acoustic Doppler current profilers in mesoscale surveys

    Publication Year: 1991, Page(s):368 - 373
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    The mesoscale structure of the Arctic Front in the Greenland Sea has been investigated during three surveys using acoustic Doppler current profiling and hydrographic measurements. It is shown that systematic errors of the current measurements that are related to the ship's speed can be reduced significantly by an appropriate calibration, and that the vessel's navigation remains the main limiting f... View full abstract»

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  • Performance of a broad-band acoustic Doppler current profiler

    Publication Year: 1991, Page(s):402 - 407
    Cited by:  Papers (69)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    A new broadband acoustic Doppler current profiler (ADCP) is described, with a useful range comparable to that of a commercially available narrowband (incoherent) system of the same acoustic frequency, but having enhanced performance. The extra performance may be traded off among (1) reduced velocity variance, (2) reduced averaging time, and (3) finer depth resolution. This improvement permits the ... View full abstract»

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  • An instrument to measure seabed boundary-layer processes

    Publication Year: 1991, Page(s):338 - 342
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    An instrumented platform for investigating the processes governing sediment resuspension and transport near the seabed is described. Water velocities at five positions, suspended-sediment concentration profiles, surface wave activity, and other parameters are measured. The data logger is extremely flexible. There is no fundamental limit to the number or type of sensors that can be fitted. Regular ... View full abstract»

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  • A comparison of two Doppler current profilers

    Publication Year: 1991, Page(s):374 - 381
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (588 KB)

    Two acoustic Doppler current profilers were tested in March 1988. The goal of the test setup was to compare two Doppler profilers under operational conditions in shallow waters. The two profilers involved were an RD-DR 1200 system and the profiler implementation on the Sonar Work Station of Rijkswaterstaat. In general, close correspondence was found between the two profilers, although under nonsta... View full abstract»

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  • Acoustic correlation current profiler

    Publication Year: 1991, Page(s):408 - 414
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    An acoustic correlation current profiler (ACCP) system is being developed to obtain vertical profiles of current velocities to ranges of approximately 1500 m. A single transmitter and a spatial array of eight receivers arranged in a novel geometry are employed to measure water mass displacement from receiver array cross-correlation functions. Test data from a shallow water ACCP operating at 76.8 k... View full abstract»

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  • Degradation of some mechanical current meter measurements by high-frequency mooring or wave motion

    Publication Year: 1991, Page(s):343 - 349
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (596 KB)

    Comparison of current measurements from moored (paddle-wheel rotor) Aanderaa current meters and acoustic Doppler current profilers in a strong tidal flow on Georges Bank indicates rate under-reading by the Aanderaa meters at some vertical positions. The under-reading may arise from mooring-line vibrations induced by vortex shedding from spherical buoyancy packages, and shielding of the paddle-whee... View full abstract»

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  • Spatial covariance and adaptive beam forming of high-frequency acoustic signals forward scattered from the sea surface

    Publication Year: 1991, Page(s):415 - 419
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    The author addresses the spatial coherence of high-frequency acoustic signals that have been forward scattered from the sea surface. The Fresnel-corrected Kirchhoff approximation is applied to derive closed-form expressions for the spatial coherence. These expressions are used to study the influence of geometrical and environmental factors on the coherence. An application of the theory involving t... View full abstract»

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  • Recent developments in ocean data telemetry at Woods Hole Oceanographic Institution

    Publication Year: 1991, Page(s):350 - 359
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (844 KB)

    The Woods Hole Oceanographic Institution is developing techniques for telemetering oceanographic data from the deep ocean to the laboratory in near real time. Three general approaches that provide a link between subsurface instruments and surface buoys equipped with satellite transmitters are being pursued. These approaches are: cabled systems that use electromechanical cables to connect subsurfac... View full abstract»

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Aims & Scope

The IEEE Journal of Oceanic Engineering (ISSN 0364-9059) is the online-only quarterly publication of the IEEE Oceanic Engineering Society (IEEE OES). The scope of the Journal is the field of interest of the IEEE OES, which encompasses all aspects of science, engineering, and technology that address research, development, and operations pertaining to all bodies of water. This includes the creation of new capabilities and technologies from concept design through prototypes, testing, and operational systems to sense, explore, understand, develop, use, and responsibly manage natural resources.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
N. Ross Chapman
School of Earth & Ocean Sciences
University of Victoria
3800 Finnerty Road
Victoria, BC V8P 5C2 Canada
chapman@uvic.ca