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1.
针对目前航道测量水深检测中主要依赖人工判读比对的主观随意性问题,探讨空间插值法在水深检测中应用的可行性。选取地形条件各异的测点样本数据,用反距离加权插值法、克里格插值法、样条函数插值法、自然邻点插值法对其插值分析。通过实验比较发现,需针对具体的地形特征选择最优空间插值法,对河床地形起伏大、水深测点密度较低的区域,空间插值误差的比对超限比例会超出规范允许的限值,故较难进行实际应用;反之,空间插值法具备应用可行性。  相似文献   

2.
海水透明度是描述海水光学特性的一个重要参数。论文首先利用现场测量的遥感反射率和透明度数据建立了西北太平洋的透明度遥感反演模型,并应用于Seawifs、MODIS-aqua、MOIDS-terra及MERIS Level 2反射率数据,获取西北太平洋的透明度数据。然后将平均法、最优插值法2种融合方法分别应用于上述4颗卫星的透明度数据进行数据融合,并用现场测量的同步透明度数据对融合后的产品进行了印证。另外,利用2种融合方法分别对西北太平洋2007年Seawifs、MODIS-aqua、MODIS-terra和MERIS4颗传感器的透明度数据进行了月融合,分析了融合的西北太平洋的时空分布特征。研究结果表明,融合数据大幅度提高了空间覆盖率,并具有较高可信度。平均法和最优插值法两种融合方法性能有较大的不同,平均法对细节特征保留的较好,且具有较高的运行速度,但有时空间覆盖率仍不能满足要求;最优插值法具有高的空间覆盖率,但其运行速度较慢。  相似文献   

3.
徐新强  方明  李军 《海洋测绘》2010,30(6):15-18
介绍了重力场模型的框架约束方法,当直接重力法模型经过已知点框架约束后,可削弱系统差,提高最终成果精度。用实测真值对重力法模型进行框架约束时,必须确定适合项目的最优空间插值法。通过对四类常用插值法的分析研究和三个实例的计算,得出依据插值要素的空间变异性和相关性,通过建立精度评估系统进行有效性评估,可以确定最优空间插值法。  相似文献   

4.
利用最优插值数据同化方法对Argo资料进行了网格化实验,得到了与WOA05较为一致的结果,验证了最优插值法对Argo资料网格化的有效性,并为加快开发制作适用于海洋模式和数据分析的Argo网格化数据集打下了很好的基础。  相似文献   

5.
利用M IT gcm模式和最优插值法搭建的同化平台对热带太平洋赤道附近的海表温度SST数据进行了数值同化处理。结果表明,同化处理有效兼顾了模式模拟值和观测值,纠正了模式模拟值出现的误差,数值同化结果更接近于观测值。该同化平台能够更好地反映出SST的分布特征,该同化方法可以有效地对海表数据进行数值预报。  相似文献   

6.
朱江  徐启春 《海洋学报》1995,17(6):9-20
利用最优插值法发展了一个海温短期数据预报的资料同化系统,并进行了一些客观分析试验。这个同化系统具有下述几个特点:(1)由于海温的保守性,在对海个时次的船舶报SST资料进行同化时,加入了前后相差6h的相邻资料作为同时资料,增加了资料密度,较好地解决了海洋资料相对稀疏引起的问题;(2)利用模式的一系列后报试验结果来估计模式预报误差的标准差,这比常用主观猜测的方法更加客观;(3)对观测资料进行检误的质量  相似文献   

7.
利用最优插值法发展了一个海温短期数据预报的资料同化系统,并进行了一些客观分析试验。这个同化系统具有下述几个特点:(1)由于海温的保守性,在对海个时次的船舶报SST资料进行同化时,加入了前后相差6h的相邻资料作为同时资料,增加了资料密度,较好地解决了海洋资料相对稀疏引起的问题;(2)利用模式的一系列后报试验结果来估计模式预报误差的标准差,这比常用主观猜测的方法更加客观;(3)对观测资料进行检误的质量  相似文献   

8.
海洋声场环境是决定海军作战行动成败的重要组成要素之一,海洋的垂直温度结构作为影响声速场的最重要因素,为了更精确更为实际的反映其分布特点,对其各种数据进行同化研究是十分必要的。文中针对海温数据来源的特点,提出了一种海温数据同化的最优插值方法,较好地完成了各种观测数据与背景数据的同化,并用各种数据进行了检验,其结果表明,利用最优插值法对海温数据进行同化处理是可行的,且同化效果比较理想。  相似文献   

9.
为了客观准确地反映海洋潮流空间分布特征,文中选取琼州海峡表层大潮流速数据,运用泛克里金插值法中的球状、指数、高斯和有理二次方程式4种不同半变异模型进行拟合插值,采用交叉验证和点验证法,通过对比4种半变异模型4个指标精度,研究结果表明在琼州海峡区域,有理二次方程式模型对表层大潮流速拟合效果最优,该研究为描述琼州海峡潮流空间分布和建立精确插值模型提供依据。  相似文献   

10.
以World Ocean Atlas(WOA)气候态月平均资料作为数据同化的背景场,以断面调查数据作为数据同化的观测场,采用最优插值法,对WOA数据进行同化处理,得到分析场,并通过一维搜索方法获得最优相关距离尺度,对分析场进行优化。将调整得到的分析场作为现场观测数据的补充,然后对其网格化并绘制等值线图。两组试验结果表明,经过同化处理后绘制得到的等值线图既保留了区域的气候态特征,又体现了观测期间的特点,在一定程度上可以避免因数据空间分辨率不足所导致的插值结果异常,较单纯使用实测数据或将实测数据与WOA数据简单叠加得到的等值线分布更合理。最优相关距离尺度的大小依同化对象数据类型的不同而不同,一维搜索方法可以较便捷的获得最优相关距离尺度,提高数据同化的效果。  相似文献   

11.
林千红 《台湾海峡》2006,25(1):130-138
区域海洋立体监测系统的建立旨在提供全面的、系统的海洋动力环境和生态环境信息共享资料,为区域性海洋防灾减灾和海洋环境管理提供实时信息的网络平台.本文通过费一效分析的方法,初步测算了台湾海峡及毗邻海域海洋动力环境实时立体监测系统潜在的年经济效益超过29692.8万元,对区域海洋管理的决策具有重要意义.  相似文献   

12.
Data on the volume concentration of carbon oxide (CO) in surface-air samples taken in European Russia, which were obtained using the Fourier transform spectroscopy method, are given. Over 16 years of measurements, this concentration decreased by 28%. These measured concentrations of CO are separated into its regional natural background and anthropogenic components. Seasonal variations in the concentration of CO are separated from its background concentration. Their extreme intra-annual values and mean amplitudes are determined. An empirical model of time variations in the concentration of CO is proposed. The atmospheric concentration of the CO anthropogenic component decreased by ~61 ppb over the measurement period.  相似文献   

13.
Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have uncertainties associated with environmental variability, measurement capabilities, conversion parameters, and processes that are not well sampled. We present these issues and quantify associated uncertainties where possible, using a Monte Carlo analysis of a published data set to determine the probability that the imbalance can be explained purely by uncertainties in measurements and conversion factors. A sensitivity analysis demonstrates that the bacterial growth efficiencies and assumed cell carbon contents have the greatest effects on the magnitude of the carbon imbalance. Two poorly quantified sources, lateral advection of particles and a population of slowly settling particles, are discussed as providing a means of closing regional carbon budgets. Finally, we make recommendations concerning future research directions to reduce important uncertainties and allow a better determination of the magnitude and causes of the unbalanced carbon budgets.  相似文献   

14.
南沙海域深水区表层沉积物声速与孔隙度相关关系   总被引:5,自引:0,他引:5  
采用同轴差距测量法对南沙海域海底沉积物取样进行甲板现场声学测量,并计算了声速,结合沉积物取样分析获得的孔隙度,研究了海底表层100 cm沉积物的声速和孔隙度之间的相互关系,分析获得了孔隙度与海底沉积物声速关系的经验公式,结果表明此海域沉积物声速的临界孔隙度为67.80%。将此公式与国内外其他学者建立的经验公式进行了对比,分析发现各预测方程之间存在着差异,说明不同海域的沉积物声学特性具有差异性,经验公式具有区域性,同时分析了其他影响声速的因素。此项工作对于建立和研究南海声场环境具有重要意义。  相似文献   

15.
As indicated by the profile of overconsolidation ratio (OCR), the stress history of a soil deposit is one of the dominant factors that influence the engineering behavior of soils. A commonly used method to obtain the parameter is the laboratory oedometer test, which is of low accuracy and time consuming because of inevitable sample disturbance. These difficulties can be overcome by in situ pizeocone penetration test, which provides continuous measurement of cone resistance, sleeve friction, and pore water pressure induced during the penetration. Though many methods have been proposed to estimate the preconsolidation pressure and overconsolidation ratio of clay deposits, their validity still needs to be proved. In this study, existing empirical methods for interpreting stress history of clays through piezocone tests are briefly reviewed. It is shown that regional correlations are valid. Piezocone tests utilizing a Vertek-Hogentogler CPTU truck that have been completed at different sites in the Jiangsu province of China. Existing correlations are compared with these field test data. It is shown that the correlation based on normalized net tip resistance is pretty accurate for determining the overconsolidation ratio of Quaternary clay deposits.  相似文献   

16.
The present tidal correction of sea level records of Satellite with ARgoes and ALtimeter (SARAL) is based on the finite element solution (FES) of global tide model FES2012 tidal solution. In this study, we examined the validity of the tidal corrections in the coastal oceans around India using tide gauge measurements and a regional tidal model. Our regional model is based on the barotropic version of the Princeton Ocean Model that is forced by the time-varying tidal levels at the open ocean end based on the global FES99 tidal solution. Tide charts prepared from the simulated tidal levels are very similar to the FES tidal solutions. Comparison with the tide gauge measurement shows close agreement with the regional tidal solutions. On the other hand, the agreement with the FES tide models differ significantly in the Gulf of Khambhat and the Gulf of Kutch on the northwest, and in the Hooghly estuary on the northeast continental shelf. However, the agreement is exceptional in other parts of the study domain. These tidal solutions are used in the SARAL-ALTIKA X-track data to assess the FES tidal correction and to draw some inferences associated with the coastal processes. It is revealed that these corrections are reasonably accurate for the coastal oceans around India except the aforementioned converging channels.  相似文献   

17.
区域经济差异是区域空间结构研究的重点问题,小尺度下区域经济差异分析更能深刻地揭示区域差异的内在机制,是解决地方经济发展问题的有效途径。本文以县域为基本单元,运用区域经济重心、泰尔指数以及专业化指数,分析探索2000年以来江苏省海洋经济时空差异演变。实证研究结果表明,江苏省海洋经济重心不断改变,总体上呈现向南偏移的趋势;江苏省海洋经济总体差异在波动中逐渐下降,总体差异主要来源于区内差异,其中连云港区内差异贡献率最大;自然资源禀赋、产业基础等是江苏六大海洋产业在沿海县域的集聚变动主要原因。  相似文献   

18.
为提高潮位预报的准确性,在具有较长潮汐观测数据的站点,基于混沌理论,对观测值与潮汐模型预测值之差所构成的余水位序列(即误差序列),采用局域线性模型的分析方法,给出可能误差预测,修正模型的预报结果,提高潮汐预报的准确性。所给例子,对预测跨度T=2 h,经局域法修正后,崇武站2007年12月份1个月预测水位统计的RMSE值减少74.7%,厦门站减少60.5%;对T=24 h,崇武、厦门两站RMSE值减小都在50%左右。  相似文献   

19.
The Bosphorus is oceanographically very complicated two-layer stratified strait where denser water from the Marmara Sea flows towards North under the lighter water which is frequently flowing from the Black Sea towards South. The water level difference between both ends of the Bosphorus varies seasonally within the range of ?0.2 and 0.6 m. The seasonal variability depends mainly on the water level changes in the adjacent basins related to the hydrological cycle, short-term changes in the atmospheric pressure and the wind characteristics. These variations together with the depth and alignment of the cross section along the strait dominate the spatial and temporal variations and sometimes sharp changes in the flow pattern in three dimensions. Although these hydrodynamic conditions are critical for all marine and hydraulic works along the Bosphorus, there was not continuous long-term measurement for a sufficient time span in the strait for detailed evaluation of the current climate. An extensive site surveying work including current, wind, pressure and water level measurements was carried out between September 2004 and January 2006 in relation to the design and construction requirements of the Bosphorus Tube Crossing Project. In this study, the characteristics of stratified flow in the Bosphorus Strait and their relation to local and regional, short- and long-term changes in the meteorological parameters are studied by using the measurement data and the results are discussed comparatively.  相似文献   

20.
利用机载GNSS反射信号反演海面风速的研究   总被引:2,自引:0,他引:2  
王迎强  严卫  符养  李萍 《海洋学报》2008,30(6):51-59
全球卫星导航定位系统的反射信号(GNSS-R)遥感技术作为一种新型的、低成本的、高机动性的海面微波遥感测风技术,与其他测风手段优势互补,可以增加测风手段的多样性,弥补局部测风手段不足的状况。研究了接收机在机载高度时,GPS反射信号功率理论模型四部分函数的性质,在此基础之上,数值模拟了机载高度下理论相关功率波形,基于海面风速对波形峰值与后沿的影响,提出了一种能够兼顾所有理论波形信息的二维插值风速反演方法。利用该方法,结合实测机载数据对海面风速进行反演,反演的风速均值与附近测站风速均值相差为1.4 m/s,与浮标数据相一致。  相似文献   

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