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1.
ENDECO水流计在实际使用中不可忽视的几个问题及解决方法 总被引：1，自引：0，他引：1
ＥＮＤＥＣＯ水流计在实际应用中往往由于操作者一时疏忽而使仪器不能正常工作,乃至造成难以弥补的损失。本文提出了在实际操作中不容忽视的几个问题并介绍了解决的方法。 相似文献
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P. G. Collar 《Ocean Engineering》1978,5(3):181-196
The measurement of near-surface current in the open sea presents difficult problems, of both sensor design and mooring in the surface wave field. However, knowledge of such currents is of considerable importance in research and offshore engineering. Consequently the development of an acoustic surface current meter has received particular attention within an experimental data buoy project which has been undertaken in the United Kingdom (DB1 Project). The development of any new sensor is necessarily followed by a thorough analysis of its performance, and it is this aspect to which this paper is devoted. The first part describes an experiment in which the displacements of drifting floats, tracked acoustically, were compared with the integrated output from the acoustic current meter: also a comparison with a buoy-mounted electromagnetic sensor. The extent of agreement between these different techniques is examined.A subsequent part discusses some longer term aspects of the performance of the current meter, which has operated almost continuously for 18 months at a test site close to the east coast of England. 相似文献
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栉孔扇贝筏式养成水层的选择 总被引：1，自引：0，他引：1
筏式养殖为目前世界上许多国家人工养殖扇贝的重要养成形式。但养殖水层、养殖方法及其解说却各不相同。为了探求栉孔扇贝筏式养成的合理水层,最大限度地提高经济效益,我们于1981年4月—1982年11月,在荣成县俚岛湾以相同的筏养形式,进行了不同水层的养殖试验。 相似文献
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A wave-height meter using a simple microwave Doppler radar,simeq10 mW in power and 10.525 GHz in frequency, is proposed so that we can measure oceanic waves effectively while the ship is steaming. It was first applied to the measurement of the variation of water level generated in a wave tank, which suggested that it is adequately applicable to the measurement of oceanic waves. A field test was carried out off the cape of Nojimazaki by installing the Doppler radar 5 m above the sea level at the bow of the ship. The result agreed reasonably well with that measured simultaneously by the ultrasonic wave-height meter installed at the same position. Another test is running successfully on a larger ship with the wave-height meter installed at 9 m above the sea level. The significant wave height measured by the present meter is being compared with that observed visually by the navigation officers. 相似文献
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本文叙述了笔者研制的“自动定时编码控制器”的工作原理,给出了它的方框图和电路原理图,采用这一技术将旧的非自动化仪表改装成自动定时测量系统,具有成本低,稳定可靠等优点。 相似文献
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电磁海流计在海洋调查和研究中起着非常重要的作用。当前被广泛应用的电磁海流计的传感器基本采用三种不同的结构形式：球形结构、盘形结构和环形结构。而三种结构形式的传感器具有各自不同的技术参数和性能。文章对不同结构形式电磁海流计传感器的特点进行简要的比较和分析。我们在研制和使用电磁海流计时，应根据不同的设计要求和特定的应用环境和条件，选择适当形式结构的传感器，力求得到良好的结果。 相似文献
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鉴于数字信号处理技术的广泛应用,数字滤波技术的诸多优点,电磁测流方法的信号微弱性,介绍了数字滤波技术在电磁海流计中的应用实例,并给出了信号分析的相关图形。 相似文献
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We analyze the contemporary methods and means of measurements of the sea level and inland waters, describe a CTD-meter designed at the Marine Hydrophysical Institute of the Ukrainian National of Science for the determination of the sea
level, formulate the requirements to the perfect meter of the water level, and demonstrate that an electronic sounding stick based on the distributed Walsh thermoprofilometers can play the role of a device of this kind. 相似文献
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Takashi Ishimaru Hirotaka Otobe Toshiro Saino Hiroshi Hasumoto Toshisuke Nakai 《Journal of Oceanography》1984,40(3):207-212
A realtime monitoring system for observing physical, biological, and optical oceanographic parameters in shallow waters was developed. It consists of a CTD with oxygen sensor, anin situ fluorometer, anin situ transmissometer, and anin situ quanta meter together with an on-deck quanta meter. The system is also equipped with a water sampling device. Water sampling can be done during the upward cast on the basis of depth profiles of temperature, salinity, oxygen,in situ fluorescence, transmittance, and underwater irradiance taken during the downward cast. 相似文献
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潮间带水沙多层位同步测量系统应用的初步研究 总被引：2，自引：0，他引：2
利用水压、光电转换原理研制成的多层位水沙同步测量系统(WCT系统)不仅可测量潮间带水位随时间的变化系列、同一层位的浊度及流速，还可以同步观测这些参数在潮间带水流剖面不同层位上的变化。野外对比试验表明，WCT系统获得的流速值与直读式流速仪的测量结果基本一致，平均相对误差为14．52％；悬沙传感器经野外现场率定获得悬沙浓度，平均相对误差为21．96％，精度比室内率定提高—倍以上。悬沙粒径是影响悬沙浓度测量精度的主要因素。此外，自然环境(如海水温盐度)的变化及仪器本身的特性也可能影响到测量结果。因此，WCT系统在潮间带的水位、流速和悬沙浓度的观测和边界层研究方面有相当潜力。 相似文献
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Based on the shear effect of internal wave currents in stratified fluid, the necessary condition for the possible existence of an internal wave and the sufficient condition under which there will be no internal wave are deduced starting from the continuity equation of incompressible fluid. The above two conditions are verified by the measured results from vertical current meter arraies at some observation stations in the Bohai Sea and the South Huanghai Sea. In the treatment of measured results, first of all, the tidal period components are separated from the measured currents by Fourier-analysis method, and then the internal wave currents of tidal period from the tidal period components in the light of some considerations. The analytical results of observed currents are well consistent with theoretical analysis. Furthermore, one can also deduce some features of internal waves therefrom. Consequently, it is concluded that the observation from a vertical current meter array is an important means to verif 相似文献
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V. M. Kushnir 《Physical Oceanography》1996,7(2):149-157
This paper considers the theoretical grounds for designing a new multi-component current velocity meter with a comprehensive
beam pattern and minimum impact of structural elements on the measurement data. The effect of technological error on the sensor's
ability to transmit acoustic signals is assessed. Information about the practical realization of the acoustic current velocity
meter is provided, together with the results of its metrological tests.
Translated by Vladimir A. Puchkin. 相似文献
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THE DEVELOPMENT of testing techniques and procedures required to understand the performance of devices used to measure water currents has proven to be one of the most difficult and challenging tasks that the oceanographic community faces. It has long been recognized that some type of controllable relative water motion was a necessary element in the process of determining the accuracy of a current meter. A widely accepted solution is the towing tank where a current meter fastened to a moving carriage is moved through "still" water. A simple measurement of carriage speed over the ground compared to the current meter's flow measurement gives an indication of the accuracy of the device. Although this approach satisfied many, a sense that this technique was not sufficient spawned a few short-lived attempts at simulating time-varying flow conditions and developing deterministic models (transfer functions) for the response of inertial transducers. In addition, mathematical modeling of the motion of buoy moorings was attempted by a variety of investigators. In the late 1960's and early 1970's, the response of a current meter to the complex time-varying ocean environment became a major issue within the oceanographic community. It was clear that this information could not be obtained by simple steady-flow tow tank testing and that either dynamic controllable techniques must be developed or our ability to characterize the measurement environment must be improved. 相似文献
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A. G. Ostrovskii A. G. Zatsepin V. A. Derevnin S. S. Nizov S. G. Poyarkov A. L. Tsybulskiy D. A. Shvoev 《Oceanology》2008,48(2):275-283
The design and application of the Akvazond moored automatic water profiling system is described. The system was developed at the Shirshov Institute of Oceanology of the Russian Academy of Sciences. The system is designed for multidisciplinary oceanological studies and environmental monitoring on the sea shelves and continental slopes. An autonomous carrier (marine elevator) for different oceanic measuring equipment was developed for the first time in the practice of Russian oceanography. It is a carrier, for example, for an acoustic Doppler current meter, a CTD-profiler, a sensor of dissolved oxygen, a fluorometer, a turbidity meter, etc. The Akvazond system has an energy resource sufficient for profiling the water column in the programming regime for up to several months. The total length of the vertical displacement of the system at a nominal capacity of the power supply reaches 200 km. The main results of the field tests of the Akvazond and preliminary scientific results of its application are presented on the basis of the results of the Black Sea-2006 expedition. 相似文献
18.
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 products and very short range resolution together with the possibility of acquiring sensible results without averaging over long time periods are features of this current meter 相似文献
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Grosskopf W. Aubrey D. Mattie M. Mathiesen M. 《Oceanic Engineering, IEEE Journal of》1983,8(4):254-271
Five measurement strategies (four in situ, one remote) for estimating directional wave spectra were intercompared in a 1980 experiment at the Coastal Engineering Research Center's Field Research Facility in Duck, NC. The systems included two pressure sensor/biaxial current meter combinations (different manufacturers), a triaxial acoustic current meter, an SXY gauge (square array of four pressure sensors), and a shore-based imaging radar. A detailed error analysis suggests sources for differences in estimated wave spectra from the different instruments; in general, they intercompare favorably. The major deviation among in situ gauges was associated with the triaxial acoustic current meter. Reliance on a vertical velocity measurement (instead of a direct pressure or sea-surface elevation measurement) can contribute additional uncertainty in directional spectral estimates. The imaging radar was successful in distinguishing multiple wave trains at the same frequency, which was not possible with the simple spectral estimation analysis applied to in situ data. However, the radar is not useful in providing accurate estimates of spectral density, nor in distinguishing multiple wave trains of different frequencies coming from the same direction. Selection of a measurement strategy for a particular need depends on the precise data requirements for that application. Although the five tested intercompared well, in practice not all are equally suitable for every application. 相似文献