Automatic Profiling System for Underice Measurements

The article is devoted to the development of an autonomous profiling system for measuring the aquatic environment under ice. The system moves up and down in the water column along a cable with a load at the lower end, which is lowered into a lane in the ice. The system carrier is designed for transporting an acoustic Doppler current profiler and a salinity, temperature, and pressure probe. The system will be useful for long-term measurements of vertical profiles of the current speed and marine environment parameters, as well as ice draft. The article describes in detail the structure and operation of the system. The hydraulic scheme of the carrier buoyancy system is presented.

     

潮间带水沙多层位同步测量系统应用的初步研究

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。     

OCTOPUS,an Octo parameter underwater sensor,for use in biological oceanography studies

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.     

海洋垂直剖面水温实时监测浮标系统研制与应用

为了实时、连续地监测獐子岛海洋牧场养殖区域不同深度的温度状况,为海洋牧场构建和运行提供数据支持,项目组自行研制了海洋垂直剖面水温实时监测浮标系统,可以在水深≤50 m、风速≤60m/s、波高≤15 m的环境下应用。该浮标系统主要包括水面浮标载体子系统和剖面链观测子系统两部分,浮标载体子系统提供了安全可靠的工作平台;而剖面链子系统上的不同位置挂有多个水下传感器,用于测量相应位置的海水温度。耐压试验、温度标定、室内拷机、现场比测、海上拷机的检定数据表明该系统无渗漏、误差小、数据接收率100%。海上运行18个月的结果同样表明,浮标系统运行稳定,数据采集和接收率高,浮标电压稳定。实践表明该浮标系统具有测温精度高、结构简单、使用方便的优点,具有广泛的应用前景。     

Attitude determination using a multi‐antenna GPS system for hydrographic applications

A four‐antenna GPS attitude determination system was used to estimate roll, pitch, and heading parameters of a 52‐meter surveying vessel in an operational marine environment. The least squares algorithm for platform attitude estimation using multiple baseline vector observables is presented. An efficient on‐the‐fly carrier phase ambiguity searching method is derived, which utilizes the Cholesky decomposition method and the known baseline constraints between the GPS antennas to construct the potential ambiguity sets on the sphere. The accuracy of the estimated attitude parameters from the GPS multi‐antenna system was assessed with an independent inertial navigation system (INS). Results from sea trials show that the proposed GPS multi‐antenna system and processing algorithms delivered a satisfactory performance under various ship maneuvers. The accuracy of GPS estimated ship attitude parameters is better than 0.06 degrees at an output rate of 10 Hz. Such a performance demonstrates a new alternative means to provide accurate, reliable, and cost‐effective ship attitude information for hydrographic applications.     

高精度CTD采水器控制系统的设计与分析

本系统是国家“８６３”任务中８１８－０２Ａ项目的重要组成部 和高精度ＣＴＤ测量仪联用,可以完成任意深度、任意时刻的采水控制功能,它采用国内外最新的技术和元器件,打破了原有的采水控制装置的设计思想,使采水器的动作完全合理准确。本文重点介绍其工作原理和关键技术。     

导波式雷达水位计在潮位观测中的应用

文中简要介绍了雷达水位计的测量原理、分类和技术特点,并将其中的导波式雷达水位计和非接触式雷达水位计与传统的浮子式水位计进行了比较,说明了导波式雷达水位计应用于一些特定条件下潮位观测的优势。基于导波式雷达水位计设计了一套水位观测系统。简要介绍了该水位观测系统的系统组成、硬件设计、软件设计。针对该水位观测系统进行了计量检定,并进行了现场安装试验。在现场实验中将导波式雷达水位计数据与浮子式水位计数据进行比较,说明了采用该设计方案进行潮位观测的可行性。     

A framework for the laboratory testing of Eulerian current measuring devices

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.     

Dynamic full-wave modeling of storm microseism propagation in an oceanic environment

The full-wave modeling of storm seismoacoustic field propagation in oceanic waveguides and at the ocean-continent border in the low-frequency range from 0.01 to 1 Hz using the numerical grid method is considered. The 2D model proposed by Press and Ewing for planar waveguides above the homogeneous elastic halfspace was chosen as a basis. The influence of a layer of deposits and features of the crust of the oceanic- and continent-type was taken into account in the more complex model. The effects of the carrier frequency, orientation of directivity diagram of the signal source, and steepness of the continental slope were investigated. A system of the second-order linear partial differential equations of hyperbolic type was solved in the process of modeling. The inertia properties and attenuation in the medium were taken into consideration. Fast-operating locally recursive nonlocally asynchronous parallel algorithms were used in the modeling, which were developed at the Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences for modeling of plasma processes. At present, these algorithms are adapted for modeling of geophysical fields. A computing system consisting of two computers based on eight-core processors is used for computations. As a result, instantaneous pictures of microseism field propagation were constructed at the specified cross sections of the medium at sequential time moments, and the microseism’s frequency spectra and synthetic seismograms were obtained for some characteristic points of aqueous medium, bottom sediment, and land. The considered algorithms of full-wave numerical modeling and the computing system can be easily adapted to the 3D variant of anisotropic and inhomogeneous media specified by analytical expressions.     

Gonadal development in Japanese medaka (Oryzias latipes) exposed to 17 β-estradiol

The purpose of this research was to evaluate the Japanese medaka (Oryzias latipes) as an ecotoxicological model for the rapid evaluation of environmental estrogens. A novel short-term (48-h) exposure to 17 β-estradiol is proposed in development of a positive control for disruption of gonadal development. Recently hatched medaka fry (30 fry per dose group) with undifferentiated gonads were exposed to 4.0, 29.4, and 115.6 μg/liter of 17 β-estradiol (acetone carrier) for 48 h in a water bath at 25 °C. The fry were then grown-out in spring water for 2 weeks, killed, and processed for histological evaluation. High lethality was encountered during the grow-out period in the 115.6 μg/liter dose group. Fry in the spring water and acetone (carrier) control groups developed into females or males. Fry exposed to 17 β-estradiol developed primarily into females or had testis-ova.     

On the determination of directional wave spectra for practical applications

The performance of various directional instruments for practical oceanographic and coastal engineering applications is examined. The emphasis is put on the application of conventional current meters equipped with high resolution pressure sensors and three element arrays. Two simulation techniques have been used to produce input data with known frequency spectrum and known directional spreading. The directional spreading is determined by the maximum likelihood method and the resulting spreading is compared with the input spreading. The performance of a conventional current meter equipped with a high resolution pressure sensor depends on the width of the directional spreading of surface waves and on the frequencies under consideration. Even for very narrow directional spreading, the current meter response is acceptable for practical applications and for shallow water deployment. In general, the current meter directional response does not depend on the direction of the incident waves. The spatial array of three wave staffs deployed in shallow water shows a similar performance to that of the current meters when the dimension of the spatial array is of the order of 1 m. This performance also does not depend on the direction of the incident waves.     

极浅海水区浅地层剖面浅层失真及校正

浅地层剖面调查是进行大陆架第四纪地质研究，浅海灾害地质研究和工程地的南调查的重要手段，剖面的质量与解释精度将对研究成果的可靠性造成直接影响。由于浅地层剖面系统的震源与水听器有一定的距离，因此它只是近似的垂直发射垂直的接收单道地震系统，当水深地了浅时造成了剖面浅层的失真，导致各层位的反射时间延迟，层与层之间双程走时缩短，计算出的层速度偏高，在地形起伏较大的区域，将造成地形失真，在潮差大的区域，计算出     

Field intercomparison of nearshore directional wave sensors

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.     

The MSL-110 small sediment trap

A simple construction of the MSL-110 sediment trap developed at the Laboratory of Physical-Geological Research of the Shirshov Institute of Oceanology, Russian Academy of Sciences, is presented. The trap is easily assembled from standard parts available at stores. The trap is easy to use, reliable, and inexpensive. It is applied for determination of sedimentary matter fluxes and their components in water columns of seas, lakes, and other water reservoirs.     

一种浅水型海流定点观测系统布放方法

介绍了采用座底式轻型仪器架进行30 m以内浅水深海流观测的两种系统布放方法:先锚后仪器架法和先仪器架后锚法。其中,详细介绍了先锚后仪器架法的布放过程,对先仪器架后锚法作了简要介绍。     

水面之上法测量水体光谱的关键技术

对水体光谱特征的研究是海洋水色遥感的基础工作之一。水体的光谱特征包括:表观光学特性和固有光学特性。在水体的表观光学特性研究方面,目前国际水色界推行的有:剖面法和水面之上法(也称表面法)。由于我国近岸水体混浊度较高,浅水区域较多,研究这类水体的表观光学特性应以水面之上法为主、剖面法为辅。介绍了水面之上法水体光谱的测量技术,就其中关键技术问题进行了讨论。     

A shipborne- type wave-height meter for oceangoing vessels, using microwave Doppler radar

A wave-height meter using a simple microwave Doppler radar,simeq10mW 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.     

The IO RAN lander: A bottom station for studying the chemical exchange at the sea bottom

The design and application of a lander (an apparatus developed at the Institute of Oceanology of the Russian Academy of Sciences (IO RAN) to study the chemical processes in the near-bottom layer) are described. The methodological foundations and design peculiarities of the lander were developed in the course of chamber experiments carried out at shallow depths with the assistance of divers. The transition to greater depths required development of a multifunctional automatic device capable of independently performing long-term surveys in the near-bottom layer, including those of the chemical exchange at the water-bottom interface.     

EPSONDE: an instrument to measure turbulence in the deep ocean

EPSONDE is a tethered free-fall profiling system used to obtain temperature microstructure and velocity turbulence data to a depth of at least 1500 m. EPSONDE, which carries a variety of slow and fast sensors, is deployed on a loose kevlar multiconductor cable by a specialized wire-handling system. Data are transmitted from this underwater unit (1792 samples per second) to a shipboard system which includes a dedicated microcomputer for data logging and online data processing. The performance of this system is demonstrated by discussing a study of turbulent mixing processes in a lens of Mediterranean water (a MEDDY) found at a depth of 1000 m in the Canary basin. These studies indicate that turbulent kinetic energy dissipation may be an important mechanism in determining the decay and lifetime of a MEDDY