共查询到20条相似文献，搜索用时 593 毫秒
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本文介绍了自动校准的温度和盐度测量技术，该技术应用在海洋863项目中水质监测浮标的温盐传感器中，自动校准技术可使传器稳定性，准确芳得到很大提高，对应用到海洋领域进行长期观测的传感器具有重要意义。 相似文献
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为得到高精度海洋ＣＴＤ测量,应考虑到仪器的几方面校准,温度、电导率和压力传感器应在固定周期（每年３次）内和在每个航次前后进行检测。校准期间测量和记录传感器漂移对修正数据十分重要,可证实传感器工作状况,校准标准本身应与基准相比测,并与其他校准实验室互校,海上校准测试对验证传感器漂移率稳定性也很重要（对电导率传感器尤为重要,当通过大洋表面油层下降时,其校准可明显变化）,如实验室校准及现场测量与单一传感 相似文献
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《海洋技术学报》2001,20(2)
YZY4— 1型温、盐传感器采用高稳定性的热敏电阻测量水温 ,年稳定性为 0 .0 2 5℃ ) ,采用电磁感应式传感器测量电导率。该传感器耐污染 ,能长期在海水中工作。传感器内单片机根据新盐标公式计算出盐度值。传感器内还设有自动校准电路 ,每次测量时自动修正漂移 ,使传感器具有较好的时间稳定性。单片机进行数据采集、变换、处理 ,最后以 RS2 32 C(CMOS电平 )或 485形式输出。传感器具有互换性。壳体采用进口 ABS塑料 ,耐海水腐蚀。该传感器可应用于海洋水温和盐度的现场测量 ,如在浮标、海洋站和船上作为海洋表层调查和海水污染监测用 … 相似文献
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NGWLMS是美国SUTRON公司为美国国家海洋调查局研制的新一代水位测量系统。它采用了新的声学水位测量技术、先进的数据采集处理装置和可靠的现场使用保证措施,成为在水位和海气参数自动测量仪器领域中最新的产品,本文对该系统的主要技术特点进行了评述,以期对我们新仪器设备的研制有所借鉴。 相似文献
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In July 2000, an array of instruments called acoustic extensometers was deployed at the Cleft segment of the southern Juan de Fuca Ridge, a seafloor observatory site selected by the National Science Foundation RIDGE Program. These instruments are designed to precisely measure horizontal deformation across the axis of a mid-ocean ridge in order to detect and quantify seafloor spreading events. The instruments were deployed in semipermanent seafloor benchmarks in a linear array that is 1.2-km long and spans the floor of the axial valley. The instruments make daily measurements of distance to their neighbors in the array by recording the round trip travel time of 100-kHz acoustic pulses, and simultaneous temperature measurements are used to correct the ranges for sound speed variations. The instruments are expected to have lifetimes of at least five years. In addition, precise pressure measurements have been made at each benchmark with a remotely operated vehicle in order to monitor for vertical deformation across the array. Preliminary results show that the resolution of the acoustic measurements is ±1-2 cm and that no abrupt deformation events occurred during the first year 相似文献
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A physical model study of combined refraction and diffraction of waves through a breakwater gap at different incident angles was conducted. Both regular and random waves with narrow and broad frequency and direction spreading were studied. Besides the presence of a mild bottom slope in the lee of the breakwater, the distribution of wave heights across the width of a navigation channel inside the model harbor was also simulated. In addition to contributing to an understanding of the phenomenon of refraction and diffraction of random waves, the relatively complete set of data obtained can serve as a benchmark for testing of numerical models. 相似文献
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在复杂的水声信道中 ,实现高速率的数据传输 ,水声换能器的带宽是一个重要的技术问题。实验中 ,为了拓宽换能器的带宽 ,我们利用圆柱形压电换能器的径向振动与液腔振动相耦合原理研制自由溢流式换能器和利用纵向振动与前盖板弯曲振动相耦合原理研制纵向振动复合棒换能器。本文介绍适应于复杂的水声信道中 ,进行高速率数据传输的两种宽频带换能器的研制 相似文献
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亚马逊热带雨林作为稳定地物目标,适合进行星载微波辐射计的外定标。但近些年亚马逊热带雨林受人为破坏严重,植被覆盖面积减少,植被覆盖率降低,适合进行外定标的区域较往年发生了变化。文中依据亚马逊热带雨林近些年的归一化植被指数(NDVI)的变化情况,发现纬度位于3°S^2°N,经度位于74°W^69°W范围内的区域植被覆盖率高,适合进行星载微波辐射计外定标。文中以AMSR2 L1R亮温数据为基准,对比分析了该区域在2015-2017年3 a的亮温变化趋势,并以此作为该区域的定标基准。分析发现,该区域在非厄尔尼诺事件期间的亮温变化趋势呈现出特定的季节变化规律:在每年的6-7月,亮温值达到最低;在11-12月,亮温值达到最高,7-11月波动上升,12-6月波动下降。在厄尔尼诺事件发生期间会出现亮温值异常现象。 相似文献
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LADCP观测和资料后处理的关键技术 总被引：4，自引：4，他引：4
针对LADCP这一崭新而又特殊的海流观测技术，系统地介绍了LADCP／CTD捆绑式测量、罗盘标定、测量设置和附加信息获取等LADCP观测中的主要技术问题。在对LADCP瓦迭式资料特点进行研究的基础上，阐释了LADCP资料后处理的关键技术：首先进行LADCP资料初处理和声速剖面校正，利用同ping剖面内相邻两水层的LADCP测量值之差等于两水层的真实速度之差这一特性，把LADCP的所有测量值转化为垂向切变流速，求出水柱内各水层的垂向切变率，对其按照一定的积分顺序进行深度积分，得到水柱内各水层相对于参考层的相对速度，利用底跟踪信息可以较直接地求出参考层的速度，也可以根据测量过程中LADCP和测船相对位置在入水时和出水时保持不变这一基本成立的假定通过GPS信息求出参考层的速度，从而得到整个水柱内各水层的绝对流速。为了提高处理结果的准确度，在资料后处理的每一处理步骤中都要特别注意相应的数据质量控制。 相似文献
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Tidal Flats are important examples of extensive areas of natural environment that remain relatively unaffected by man. Monitoring of tidal flats is required for a variety of purposes. Remote sensing has become an established technique for the measurement of topography over tidal flats. A further requirement is to measure topographic changes in order to measure sediment budgets. To date there have been few attempts to make quantitative estimates of morphological change over tidal flat areas. This paper illustrates the use of remote sensing to measure quantitative and qualitative changes in the tidal flats of Morecambe Bay during the relatively long period 1991–2007. An understanding of the patterns of sediment transport within the Bay is of considerable interest for coastal management and defence purposes. Tidal asymmetry is considered to be the dominant cause of morphological change in the Bay, with the higher currents associated with the flood tide being the main agency moulding the channel system. Quantitative changes were measured by comparing a Digital Elevation Model (DEM) of the intertidal zone formed using the waterline technique applied to satellite Synthetic Aperture Radar (SAR) images from 1991–1994, to a second DEM constructed from airborne laser altimetry data acquired in 2005. Qualitative changes were studied using additional SAR images acquired since 2003. A significant movement of sediment from below Mean Sea Level (MSL) to above MSL was detected by comparing the two Digital Elevation Models, though the proportion of this change that could be ascribed to seasonal effects was not clear. Between 1991 and 2004 there was a migration of the Ulverston channel of the river Leven north-east by about 5 km, followed by the development of a straighter channel to the west, leaving the previous channel decoupled from the river. This is thought to be due to independent tidal and fluvial forcing mechanisms acting on the channel. The results demonstrate the effectiveness of remote sensing for measurement of long-term morphological change in tidal flat areas. An alternative use of waterlines as partial bathymetry for assimilation into a morphodynamic model of the coastal zone is also discussed. 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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水体吸收衰减系数测量仪定标技术 总被引：2，自引：1，他引：1
水体吸收衰减系数是水色遥感的重要参数,其现场准确测量的关键是测试仪器的严格定标.文章将围绕美国Wetlabs公司生产的水体吸收衰减系数测量仪AC9（Absorption and Attenuation Meter）的定标技术,以及定标中的注意事项进行阐述. 相似文献