排序方式： 共有16条查询结果，搜索用时 906 毫秒
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ERS散射计全球海面风场数据处理与ElNino海面风场异常观测 总被引：1，自引：0，他引：1
星载散射测量技术是获取全球海面风场的有效手段。该文研究了欧洲遥感卫星（ＥＲＳ） 散射计全球海面风场数据的处理分析技术。对１９９７ 年３ 月、６ 月和１２ 月的全球海面风场数据进行平均处理,并同时与１９９６ 年６ 月和１９９５ 年１０ 月的观测数据进行对比,利用遥感技术发现了赤道太平洋西部的风场异常,从遥感资料上分析了１９９７ 年Ｅｌ Ｎｉｎｏ 现象的海面风场（ 风速与风向） 异常变化特征。研究结果显示了星载微波散射计在全球变化监测中的重要作用。 相似文献
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Hui Feng Doug Vandemark Yves Quilfen Bertrand Chapron Brian Beckley 《Ocean Engineering》2006,33(11-12):1431-1461
The study presents assessment of an operational wave model (Wavewatch III), focusing upon the model sensitivity to wind-forcing products. Four wind fields are used to drive the model, including the NCEP/NCAR reanalysis and three other products that assimilate various satellite wind measurements having high spatial resolution, including the QuikSCAT scatterometer. Three wave field statistics: significant wave height, mean zero-crossing wave period, and mean square slope are compared with collocated TOPEX altimeter derivatives to gauge the relative skill of differing wind-forced model runs, as well as to demonstrate an extended use of the altimeter beyond simply supplying wave height for wave model validation and assimilation. Results suggest that model output is critically sensitive to choice of the wind field product. Higher spatial resolution in the wind fields does lead to improved agreement for the higher-order wave statistics. 相似文献
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Raj Kumar Suchandra A. Bhowmick Sulagna Ray Vihang Bhatt Suhe Surendran Sujit Basu Abhijit Sarkar Vijay K. Agarwal 《Natural Hazards》2009,49(2):275-291
Accurate prediction of ocean surface waves is a challenging task with many associated difficulties. Availability of good quality
wind and wave information from satellite platforms inspired the scientific community to assimilate such data in various spectral
wave models for enhancing the accuracy of prediction. Over the Indian Ocean, which is the region of interest for the present
study, wave heights in extreme situation can go up to 12–14 m, thereby increasing the probability of coastal hazards. This
region is further governed by the southern ocean swells that propagate thousands of kilometers. These are, in general, not
well captured by the spectral wave models. Therefore, assimilation of altimeter data in open ocean wave model WAM has been
attempted with the aim of enhancing the quality of prediction of significant wave height. Further, simulated wave spectra
have been assimilated in a coastal wave model SWAN. This assimilation has been found to significantly improve the prediction
of the height of wind waves as well as swell waves.
V. Bhatt and S. Surendran are former students of Meteorology and Oceanography Group, Space Applications Centre, ISRO, Ahmedabad. 相似文献
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Observations of urban and suburban environments with global satellite scatterometer data 总被引：1，自引：0，他引：1
S.V. Nghiem D. Balk E. Rodriguez G. Neumann A. Sorichetta C. Small C.D. Elvidge 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(4):367-380
A global and consistent characterization of land use and land change in urban and suburban environments is crucial for many fundamental social and natural science studies and applications. Presented here is a dense sampling method (DSM) that uses satellite scatterometer data to delineate urban and intraurban areas at a posting scale of about 1 km. DSM results are analyzed together with information on population and housing censuses, with Landsat Enhanced Thematic Mapper Plus (ETM+) imagery, and with Defense Meteorological Satellite Program (DMSP) night-light data. The analyses include Dallas-Fort Worth and Phoenix in the United States, Bogotá in Colombia, Dhaka in Bangladesh, Guangzhou in China, and Quito in Ecuador. Results show that scatterometer signatures correspond to buildings and infrastructures in urban and suburban environments. City extents detected by scatterometer data are significantly smaller than city light extents, but not all urban areas are detectable by the current SeaWinds scatterometer on the QuikSCAT satellite. Core commercial and industrial areas with high buildings and large factories are identified as high-backscatter centers. Data from DSM backscatter and DMSP nighttime lights have a good correlation with population density. However, the correlation relations from the two satellite datasets are different for different cities indicating that they contain complementary information. Together with night-light and census data, DSM and satellite scatterometer data provide new observations to study global urban and suburban environments and their changes. Furthermore, the capability of DSM to identify hydrological channels on the Greenland ice sheet and ecological biomes in central Africa demonstrates that DSM can be used to observe persistent structures in natural environments at a km scale, providing contemporaneous data to study human impacts beyond urban and suburban areas. 相似文献
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The problem of selecting the optimum operating frequency of a scatterometer, used for remote sensing of sea surface wind speed
has been addressed by applying the criteria of maximum sensitivity of backscattering coefficient to wind speed as well as
its correlation with wind speed. The backscattering coefficient values for sea surface were computed by the two-scale scattering
theory. To compute the atmospheric transmittance, 753 clear sky atmospheres over Indian Ocean were used. While the correlation
coefficient was uniform (0.94) throughout the frequency range of 1 to 30GHz, only frequencies above 5GHz were found sensitive
enough to yield a wind speed accuracy of ±2msec−1 and better, the accuracy improving with frequency. 相似文献
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一种修正的星载散射计反演海面风场的场方式反演算法 总被引：10，自引：0，他引：10
由于卫星散射计探视雷达回波的各向异性的双调和性质,同时由于散向散射物理模型函数的非线性及信号中存在噪声,使得常规点方式风场反演哕向有多至４个解的多解存在。给出了一种改进的场方式钣演方法,利用该人卫星散射计测量的后向散射强度的数据中唯一反演出大尺度海洋风场。通过数值模拟和实际算例计算表明反演过程在风向、风速上都与真解是吻合的。从结果可以看到,所采用的改进的场方式反演方法对模拟数据或真实散射计探测海面 相似文献
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