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Date Sept. 28 1987-Oct. 1 1987

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Displaying Results 1 - 25 of 352
  • [Front cover and table of contents]

    Publication Year: 1987, Page(s): 0
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    Freely Available from IEEE
  • [Back cover]

    Publication Year: 1987, Page(s): 0
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    Freely Available from IEEE
  • 1987 Preseason Iceberg Survey and Season Prediction

    Publication Year: 1987, Page(s):1 - 4
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (219 KB)

    During January, February, and March 1987, the International Ice Patrol (U. S. Coast Guard) and the Ice Branch of the Atmospheric Environment Service of Canada conducted a joint iceberg survey utilizing their side looking airborne radar equipped patrol aircraft. This international cooperative study was the latest in a history of mutually beneficial efforts extending back to 1961. The 1987 preseason... View full abstract»

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  • Innovations in Dynamic Modelling of Iceberg Drift

    Publication Year: 1987, Page(s):5 - 10
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (445 KB)

    Dynamic models of iceberg drift require as input the currents and winds which drive the iceberg, but in the past it has not been possible to obtain adequate data on currents. Two cruises of CSS Dawson have collected data for the testing and development of a dynamic iceberg drift model, with current profiles continuously monitored by a doppler current profiler. Winds were measured by an anemometer ... View full abstract»

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  • Long-Range Forecasting of Iceberg Season Severity

    Publication Year: 1987, Page(s):11 - 16
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    The development of statistical schemes for the long-range prediction of Grand Banks iceberg season severity is described. Empirical Orthogonal Function (EOF) Analysis is employed to isolate the dominant modes of variability in atmospheric pressure, geopotential height, thickness and air temperature predictor fields over a broad region of the North Atlantic. Correlations between eigenfunction coeff... View full abstract»

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  • Statistical Properties of Iceberg Motion at the Western Entrance of Lancaster Sound

    Publication Year: 1987, Page(s):17 - 23
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (538 KB)

    The Lagrangian autocorrelation coefficient, of velocities with the local mean current extracted, has e-folding time scales of 15 and 22 hours for the x and y components of motion respectively. Periodicities that might be attributed to either semidiurnal tides or inertial oscillations are evident, as are diurnal periodicities. Local vorticity is typically 5 times greater than local divergence and, ... View full abstract»

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  • Ice Forces on Offshore Structures; Model and Full Scale Comparison and Future Improvements

    Publication Year: 1987, Page(s):24 - 29
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (552 KB)

    Ice model tests of Gulf Canada Corporation's floating drilling structure, the "Kulluk" were carried out prior to its construction by Arctec Canada Limited using our synthetic modelling material, MOD-ICE(1). The tests were carried out in level ice and in broken ice sheets 0.5 to 1.5 m in thickness. The resistance of the model in these ice conditions was measured and the associated ice interaction p... View full abstract»

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  • Ice-Induced Dynamic Behaviour of Structures

    Publication Year: 1987, Page(s):30 - 34
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    Ice research is continually challenged by new questions, The questions have evolved from the basic knowledge of ice strength itself to the evaluation of indentation forces. Even though some work is still needed to assess the reliability of values of static ice loads on large structures, the major concern lately relates to dynamic loading. The vibration of a structure on a regular basis can cause f... View full abstract»

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  • MV Arctic Vessel Performance and Trafficability Program

    Publication Year: 1987, Page(s):35 - 41
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (631 KB)

    Ice, environmental and navigation information has been collected on board the MV ARCTIC by dedicated observers, for all voyages north of 60 degrees north latitude since 1983. These data reside on the Interactive Data Input, Analysis and Display System (IDIADS), user friendly micro-computer based work station developed in 1986/87 to manage the growing data base relating navigational information to ... View full abstract»

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  • The Nonlinear Heave Motion and Wave Forces on a Partially Submerged Sphere

    Publication Year: 1987, Page(s):42 - 48
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (559 KB)

    An experimental and theoretical investigation to examine the nonlinear response of small ice masses to a wide range of wave excitations has been conducted. The motion of a free floating spherical model in a regular wave field ranging in length from .61 to 5.6 m and in steepness from 1/100 to 1/10 has been analyzed. Measured heave motions and forces in the direction of surge of a towed model in wav... View full abstract»

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  • An Improved Salargos Buoy for Deployments in Polar Seas

    Publication Year: 1987, Page(s):49 - 53
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    An improved oceanographic and meteorological data collection buoy system called SALARGOS has been developed for deployments in polar seas for periods of up to two years. Recent Arctic deployments were made using spar buoys with 300 meter sensor strings each equipped with six temperature/conductivity sensor pairs. Data relay is carried out using the ARGOS capability of the two orbiting NOAA Satelli... View full abstract»

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  • An Arctic Remote Autonomous Measurement Platform

    Publication Year: 1987, Page(s):54 - 58
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (383 KB)

    Perpetual ice cover in the Arctic inhibits broad analysis of the region. Ice camps and research ships do not provide sufficient temporal and spatial coverage. Satellites expand the coverage, but only within the limits of on-board sensors. A multidisciplinary data collection tool is needed to expand coverage in ice covered regions. The Arctic Remote Autonomous Measurement Platform (ARAMP) is a drif... View full abstract»

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  • Development and Recovery of Oceanographic Moorings through Drifting Sea Ice

    Publication Year: 1987, Page(s):59 - 65
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (611 KB)

    First Page of the Article
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  • Mechanical Design Solutions for Buoys to be Used in the Marginal Ice Zone

    Publication Year: 1987, Page(s):66 - 69
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    A series of four hulls were to be designed for launch either in open water or through ice in the marginal ice zone (MIZ). This paper reports on solutions implemented up to the third buoy of the series. Maintaining structural integrity for each of these buoys is critical to their survival. The units must be small enough to permit insertion via an eight inch hole if deployed through the ice, they mu... View full abstract»

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  • Generation of a Probabilistic Climatology for Arctic Sea Ice

    Publication Year: 1987, Page(s):70 - 75
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    The climatology of sea ice has lagged behind that of waves, currents and atmospheric conditions. Where other climatologies have been expressed in probabilistic terms useful to design engineers and planners, this approach has been used for floating ice only on a site-specific basis. A probabilistic climatology for the arctic shipping zones would greatly facilitate on-going work in the design and re... View full abstract»

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  • Winter MIZEX 87, Operations Overview

    Publication Year: 1987, Page(s):76 - 82
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (759 KB)

    MIZEX (Marginal Ice Zone Experiment), a multinational, interdisciplinary study of the Arctic environment, has the overall goal to better understand the mesoscale interaction of ice, ocean, and atmosphere at the polar margin. Winter MIZEX is the natural extension of the successful 1983-84 Summer programs and this paper presents an overview of the MIZEX 87 operations, March 19 to April 13, 1987. Pri... View full abstract»

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  • Bottom Currents Measured with a Pulse-to-Pulse Coherent Sonar

    Publication Year: 1987, Page(s):83 - 88
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (434 KB)

    The performance of a High Resolution Current Profiler (HRCP) using pulse-to-pulse coherent Doppler technique rather than conventional incoherent Doppler (ADCP) technique is discussed. The HRCP (300 KHz) was deployed on the bottom of the North Sea (at about 100 m depth) looking upwards. The sensor head was deployed separately form the electronics and communication was achieved by cable. The main fr... View full abstract»

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  • Coded Pulse-Coherent Doppler Sonar

    Publication Year: 1987, Page(s):89 - 92
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    We describe the use of coded pulse trains to improve the range-velocity ambiguity of pulse-coherent Doppler sonar. Laboratory results are presented, together with a discussion of the performance of a Doppler estimator based on Fourier transform methods. An instrument incorporating these ideas, and intended for high-resolution turbulence measurements is briefly described. View full abstract»

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  • Development of a Practical Coherent Acoustic Doppler Current Profiler

    Publication Year: 1987, Page(s):93 - 97
    Cited by:  Papers (12)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (413 KB)

    The practical feasibility of developing a Coherent Acoustic Doppler Current Profiler (ADCP) with spatial resolution and range comparable to those of commercially available incoherent systems but with much smaller velocity measurement variance is being studied. This improvement in measurement accuracy will reduce required averaging times, thus permitting the observation of short time-scale currents... View full abstract»

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  • Development of a Real Time Measurement System for Charleston Harbour

    Publication Year: 1987, Page(s):98 - 103
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (646 KB)

    The National Ocean Service of NOAA has developed and deployed a real-time current measuring system for verification of the accuracy of the NOAA tidal current table for Charleston Harbor. An RD Instruments acoustic Doppler current profiler on the bottom of Charleston Harbor is hard wired to a Coastal Climate weather station. The weather station transmits both the weather data and the current profil... View full abstract»

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  • A Microcomputer System for a Shipboard Doppler Current Profiler

    Publication Year: 1987, Page(s):104 - 109
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (479 KB)

    Microcomputers are now sufficiently powerful to permit cost-effective implementation of improved real-time Doppler Current Profiler data acquisition, processing, and multipurpose display systems. An IBM-PC/XT microcomputer based system is described for use with the Ametek/Straza DCP 4400A/300. The system, in conjunction with a compound pendulum stabilized ship's motion sensing package, performs ge... View full abstract»

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  • Acoustic Doppler Current Profiling from Moored Subsurface Floats

    Publication Year: 1987, Page(s):110 - 116
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (555 KB)

    A Doppler Acoustic Profiling Current Meter (DAPCM) was deployed in a sphere at the top of a subsurface mooring in the swift currents of the Strait of Gibraltar. Larger than expected currents caused vertical mooring excursions that in one case exceeded 150 m. Despite these mooring motions, nearly continuous time series were maintained at fixed depths between 40-240 m. Mooring design, performance, a... View full abstract»

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  • Motion Compensation for a Shipboard Doppler Current Profiler, Considerations and Implementation

    Publication Year: 1987, Page(s):117 - 122
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (454 KB)

    Velocity profiles generated from a non-motion compensated Doppler current profiler in a moving shipboard reference frame are subject to a number of systematic distortions. The effect of neglecting the instantaneous static orientation of an AMETEK STRAZA DCP4400A/300 shipboard profiler is illustrated using an approximate numerical model and reference to pitch and roll ground truth data collected ab... View full abstract»

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  • An Acoustic System for Measuring Ocean Flows by Space-Time Scintillation Analysis

    Publication Year: 1987, Page(s):123 - 129
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (573 KB)

    We describe an acoustic measurement system built to test several techniques for analyzing a forward-scattered sound field in the ocean. The fluctuations of the sound field contain information about the field of flow along the acoustic path. The instrument consists of a microprocessor-controlled, radio-linked transmitter with a 4-element array, a 4-element receiving array and a receiver incorporati... View full abstract»

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  • The Acoustic Measurement of Plankton Population Density

    Publication Year: 1987, Page(s):130 - 133
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (346 KB)

    Measurement of the density of populations of particles or organisms in suspension in a fluid has been a matter of interest for some years. This paper outlines some of the underlying principles involved in using acoustic backscatter and gated, echo-squared integration to perform such measurements, It presents the Gamma distribution as the statistical descriptor for the integrator output. It then de... View full abstract»

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