共查询到19条相似文献,搜索用时 562 毫秒
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卫星测高在确定地球重力场中的应用 总被引:2,自引:1,他引:2
根据测高所得的几何量与地球重力场物理量之间的关系,探讨了卫星测高数据在确定地球重力场参数中的应用,主要包括利用卫星测高数据确定海洋大地水准面、确定海洋重力异常和改善地球重力场模型。 相似文献
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海洋背景磁场模拟计算及东中国海表层磁场分布 总被引:1,自引:0,他引:1
海洋中海水的运动会切割地球磁场,生成微弱的电场,进而在海洋内部和周围空间激发感生电磁场,即约为地球磁场一万至十万分之一的微弱海洋背景磁场.文中针对海洋背景磁场的生成机制及近几十年来对海洋背景磁场的理论研究,结合世界磁场模型WMM2005,模拟计算了三种典型的海洋运动--海浪、海流、内波所产生的感应磁场,建立了海洋背景磁场的数值计算模型,并在此基础上设计开发了海洋背景磁场的模拟计算软件.最后用卫星多传感器资料驱动普林斯顿海洋动力学模式,得到的东中国海2005年海洋表层环流数据,模拟计算了东中国海海表层磁场分布,对其磁场变化与分布规律作了简要分析. 相似文献
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以中国南海部分海域作为试验区,依据测区船载重力测量结果分别对S&S V28.1、S&S V29.1、DTU15和DTU17卫星测高海洋重力场模型开展了精度评估与分析工作。首先利用EIGEN6C4超高阶位系数模型计算得到的参考重力异常,使用多项式拟合技术对船载重力异常进行了长波误差改正;然后借鉴3σ准则进一步控制船载重力测量结果质量;最后以RMS作为精度主要评价指标,完成了对4种海洋重力场模型精度评估。结果表明,4种海洋重力场模型检核精度整体相当,其中S&S V29.1检核精度略高于S&S V28.1,4种重力异常模型在试验海域精度大致在1.5~6mGal之间。试验结论对于后续重力场模型应用具有一定参考价值。 相似文献
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卫星测高中的垂线偏差法 总被引:6,自引:0,他引:6
卫星测高中的垂线偏差法是当前利用卫星测高技术研究海洋重力场的最优方法,包括利用卫星测高数据计算垂线偏差和利用该垂线偏差确定海洋重力场两部分。研究了Sandwell、Olgiafi、Hwang测高垂线偏差的计算方法和Molodenskii、Hwang利用测高垂线偏差确定海洋重力场的基本原理,分析比较了上述方法的异同,为科学地利用卫星测高资料反演海洋重力场提供理论依据。 相似文献
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海洋政策的制定和实施不可能是孤立的,一方面,随着时间的推移,人类在海洋中活动能力日益增强,海上活动不断频繁,海洋事务日趋复杂,海洋政策不断变化;另一方面,随着人类对海洋的开发越来越深入,海洋政策包含的内容也越来越多,体现出综合性、跨部门性的特点。因此,围绕海洋政策的研究,就产生了两条路径:纵向的历史研究;横向的部门海洋政策研究。文章采用这两种研究方法,对我国海洋政策做了回顾梳理,并对未来海洋政策的发展进行了展望。 相似文献
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自20世纪70年代以来,我国海洋经济迅速发展,取得了有目共睹的成就。尤其是《中国海洋21世纪议程》的颁布,标志着我国海洋经济的发展走向了可持续发展的道路。海洋经济可持续发展的实践一方面丰富了海洋经济理论的研究成果,推动了海洋经济理论研究的深入和发展,并促使海洋经济呈现出多学科综合研究的态势;另一方面也提出了一系列亟需解决的现实问题,迫切要求有科学的海洋经济理论来指导海洋经济的实践活动,促使海洋经济活动真正沿着可持续的方向发展。现实的需要促成了海洋经济学的兴起,同样也要求海洋经济学迅速成熟并能对海洋经济的发展起… 相似文献
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HY-2 A(Haiyang-2 A), launched in 2011, is the first ocean dynamic environment satellite of China and is equipped with a radar altimeter as one of the primary payloads. HY-2 A shifted the drift orbit in March 2016 and has been accumulating geodetic mission(GM) data for more than three years with 168-day cycle. In this paper, we present the preliminary gravity field inverted by the HY-2 A/GM data from March 2016 to December 2017 near Taiwan(21°–26°N, 119°–123°E). The gravity anomaly is computed by Inverse Vening Meinesz(IVM) formula with a onedimensional FFT method during remove-restore procedure with the EGM2008 gravity model as the reference field. For comparison, CryoSat-2 altimeter data are used to inverse the gravity field near Taiwan Island by the same method. Comparing with the gravity field derived from CryoSat-2, a good agreement between the two data sets is found. The global ocean gravity models and National Geophysical Data Center(NGDC) shipboard gravity data also are used to assess the performance of HY-2 A/GM data. The evaluations show that HY-2 A and CryoSat-2 are at the same level in terms of gravity field recovery and the HY-2 A/GM altimeter-derived gravity field has an accuracy of 2.922 mGal. Therefore, we can believe that HY-2 A will be a new reliable data source for marine gravity field inversion and has the potentiality to improve the accuracy and resolution of the global marine gravity field. 相似文献
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以南通幅海洋重力编图为例,论述了如何应用海洋重力与陆地重力以及卫星重力数据等不同来源的重力数据进行海洋重力编图。讨论了编图中关键问题,如各种数据的统一改算问题,包括统一的重力基准网、统一的正常重力公式、统一的投影方式;不同来源数据间的拼接调平问题;卫星重力数据使用范围问题等,并对最新的南通幅编图结果与以往相同范围内的编图进行了比较。 相似文献
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海洋生物技术前沿领域研究进展 总被引:3,自引:0,他引:3
根据近期国际海洋生物技术研究发展的有关信息资料,介绍了海洋生物技术研究的现状、前沿领域和最新研究进展,并展望了今后的发展趋势及我国应采取的措施。 相似文献
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With the advent of satellite altimetry in 1973, new scientific applications became available in oceanography, climatology, and marine geosciences. Moreover, satellite altimetry provides a significant source of information facilitated in the geoid determination with a high accuracy and spatial resolution. The information from this approach is a sufficient alternate for marine gravity data in the high-frequency modeling of the marine gravity field quantities. The gravity gradient tensor, consisting of the second-order partial derivatives of the gravity potential, provides more localized information than gravity measurements. Marine gravity observations always carry a high noise level due to environmental effects. Moreover, it is not possible to model the high frequencies of the Earth's gravity field in a global scale using these observations. In this article, we introduce a novel approach for a determination of the gravity gradient tensor at sea level using satellite altimetry. Two numerical techniques are applied and compared for this purpose. In particular, we facilitate the radial basis functions (RBFs) and the harmonic splines. As a case study, the gravitational gradient tensor is determined and results presented in the Persian Gulf. Validation of results reveals that the solution of the harmonic spline approach has a better agreement with a theoretical zero-value of the trace of the Marussi gravitational gradient tensor. However, the data-adaptive technique in the RBF approach allows more efficient selection of the parameters and 3-D configuration of RBFs compared to a fixed parameterization by the harmonic splines. 相似文献
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The knowledge of the bedrock topography (instead of the ocean-floor relief) is required in various geoscience studies investigating the evolution and structure of the oceanic lithosphere. The gross density structure and thickness of marine sediments were obtained from ocean drilling data or seismic surveys. Alternatively, marine gravity data corrected for the ocean and sediment density contrasts can be used for a detailed mapping of the bedrock topography. In this study, we compute and apply the sediment stripping correction to marine gravity data. The sediment density distribution is approximated by a 3-D density model derived based on the analysis of density samples from the Deep Sea Drilling Project. Methods for a spherical harmonic analysis and synthesis are utilized in computing the sediment stripping correction. Results show that this correction varies between 0 and 32 mGal. We also demonstrate that the approximation of heterogeneous sediment structures by a uniform density model yields large errors. The spectral analysis reveals a high correlation (>0.75) between the sediment-stripped marine gravity data and the bedrock topography. The application of the sediment stripping correction to marine gravity data enhanced the gravitational signature of the sediment-bedrock interface. 相似文献
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