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A Collaborative Simplification Method for Multiple Coastlines Based on the Hierarchical Triangulation Network Partition

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Journal of Geodesy and Geoinformation Science 2020年第2期3卷 93-104页

作者： Lihua ZHANG Lulu TANG Shuaidong JIA Zeyuan DAI department of military oceanography and hydrography&cartography Dalian Naval AcademyDalian 116018China

For the current automatic coastline generalization method,only one-line element is considered separately,but the relationship between the nearby elements is not effectively considered.A synergistic simplification method for multiple coastlines based on the hierarchical triangulation network partition(HTNP)is proposed in this ***,the constrained Delaunay triangulation is constructed to partition the regions that can be ***,a hierarchical binary tree model to structure the morphological characteristics of the above several coastlines and the spatial proximity between different coastlines is ***,the small curved and curved invisible parts of the coastline are deleted according to the visual constraints,and the narrow part between the coastline itself or the different coastlines is exaggerated appropriately,and the automatic simplification of the coastline is *** experimental results show that:①Relationships between the different coastlines are considered,and the shortcomings of considering the coastline separately are overcome;②Under the condition of the multiple coastlines in complex sea areas,the problem of collaborative simplification is solved,the quality of the coastlines are improved obviously,and the proposed method can be applied into more types of coastlines.

关键词： cartographic generalization coastline simplification hierarchy relationship synergistic simplification

An evaporation duct prediction model coupled with the MM5

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Acta Oceanologica Sinica 2015年第5期34卷 46-50页

作者： JIAO Lin ZHANG Yonggang department of military oceanography Dalian Naval Academy

Evaporation duct is an abnormal refractive phenomenon in the marine atmosphere boundary layer. It has been generally accepted that the evaporation duct prominently affects the performance of the electronic equipment over the sea because of its wide distribution and frequent occurrence. It has become a research focus of the navies all over the world. At present, the diagnostic models of the evaporation duct are all based on the Monin-Obukhov similarity theory, with only differences in the flux and character scale calculations in the surface layer. These models are applicable to the stationary and uniform open sea areas without considering the alongshore effect. This paper introduces the nonlinear factor a and the gust wind item wg into the Babin model, and thus extends the evaporation duct diagnostic model to the offshore area under extremely low wind speed. In addition, an evaporation duct prediction model is designed and coupled with the fifth generation mesoscale model （MMS）. The tower observational data and radar data at the Pingtan island of Fujian Province on May 25-26, 2002 were used to validate the forecast results. The outputs of the prediction model agree with the observations from 0 to 48 h. The relative error of the predicted evaporation duct height is 19.3% and the prediction results are consistent with the radar detection.

关键词： evaporation duct diagnosis mesoscale model (MM5) evaporation duct prediction model numerical simulation

TIN_DDM Buffer Surface Construction Algorithm Based on Rolling Ball Acceleration Optimization Model

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Journal of Geodesy and Geoinformation Science 2020年第3期3卷 88-103页

作者： Jian DONG Zhiheng ZHANG Rencan PENG Gaixiao LI Mo WANG department of military Oceanograhy and hydrography&cartography Dalian Naval AcademyDalian 116018China Key Laboratory of Hydrographic Surveying and Mapping of PLA Dalian Naval AcademyDalian 116018China

In view of the TIN_DDM buffer surface existing in the construction and application of special data type,algorithm efficiency and precision are not matching;the paper applied the rolling ball model in the process of TIN_DDM buffer surface *** on the precision limitation analysis of rolling ball model,the overall precision control method of rolling ball model has been *** the efficiency requirement of TIN_DDM buffer surface construction,the influence principle of key sampling points and rolling ball radius to TIN_DDM buffer surface construction efficiency has been elaborated,and the rule of identifying key sampling points has also been ***,by erecting the numerical relationship between key sampling points and rolling ball radius,a TIN_DDM buffer surface construction algorithm based on rolling ball acceleration optimization model has been brought *** time complexity of the algorithm is O(n).The experiments show that the algorithm could realize the TIN_DDM buffer surface construction with high efficiency,and the algorithm precision is controlled with in 2σ.

关键词： TIN_DDM rolling ball model buffer surface construction algorithm precision algorithm efficiency

A Line-Surface Integrated Algorithm for Underwater Terrain Matching

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Journal of Geodesy and Geoinformation Science 2019年第4期2卷 10-20页

作者： Lihua ZHANG Xianpeng LIU Shuaidong JIA Yan SHI department of military oceanography and hydrography and cartography Dalian Naval AcademyDalian 116018China Unit 31109 The Chinese People’s Liberation ArmyNanjing 210000China

The current underwater terrain surface matching algorithm,which uses Hu moment as the similarity index,cannot gain accurate location due to the algorithm’s disadvantage in detecting slight *** solve this problem,a line-surface integrated terrain matching algorithm is ***,the similarity evaluation method of the traditional Terrain Contour Matching(TERCOM)algorithm is improved,and the strategy used to select the matching regions is ***,a surface matching algorithm based on the geometric similarity is established to determine the optimum match between the reference maps and the actual measured ***,a means of“line matching algorithm”and“surface matching algorithm”integration is proposed based on a fixed *** experimental results show that the proposed algorithm can obtain a more accurate location and has greater robustness than that of the surface underwater matching algorithm based on Hu moment.

关键词： terrain matching integrated matching surface matching algorithm multi-beam bathymetric system

Application of Maximum Entropy Principle to Studying the Distribution of Wave Heights in A Random Wave Field

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海洋工程：英文版 2004年第1期18卷 69-78页

作者：周良明郭佩芳王强杜伊 department of oceanography

Based on the maximum entropy principle, a probability density function (PDF) is derived for the distribution of wave heights in a random wave field, without any more hypothesis. The present PDF, being a non-Rayleigh form, involves two parameters: the average wave height H— and the state parameter γ. The role of γ in the distribution of wave heights is examined. It is found that γ may be a certain measure of sea state. A least square method for determining γ from measured data is proposed. In virtue of the method, the values of γ are determined for three sea states from the data measured in the East China Sea. The present PDF is compared with the well known Rayleigh PDF of wave height and it is shown that it much better fits the data than the Rayleigh PDF. It is expected that the present PDF would fit some other wave variables, since its derivation is not restricted only to the wave height.

关键词： information entropy wave heights maximum entropy probability density function Rayleigh distribution

Regional hard coral distribution within geomorphic and reef flat ecological zones determined by satellite imagery of the Xisha Islands,South China Sea

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Chinese Journal of Oceanology and Limnology 2017年第3期35卷 501-514页

作者：左秀玲苏奋振赵焕庭张君珏王琦吴迪 State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Collaborative Innovation Center of South China Sea Studies Nanjing 210093China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Key Laboratory of hydrography and cartography of PLA Department of Hydrography and CartographyDalian Naval AcademyDalian 116018China

Coral reefs in the Xisha Islands （also known as the Paracel Islands in English）, South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef fiat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health （live versus dead cover） for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was 〈10%. The total Xisha reef system was estimated to cover 1 060 km2, and the emergent reefs covered -787 km2. Hard corals of emergent reefs were considered to cover 97 km2. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems.

关键词： coral reef geomorphic zone remote sensing Xisha Islands South China Sea

Application of SAR Imagery in Submarine Topography Surveys

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Marine Science Bulletin 2004年第1期6卷 38-46页

作者：张宁川梁开龙桂力民 department of hydrography and cartography Dalian Naval AcademyDalian 116018Liaonin China

An important research area in oceanographic surveying and mapping is to obtain submarine topography by remote sensing technique, especially by SAR imagery. In this article, problems related to SAR imagery are analyzed... 详细信息

关键词：地形测量海洋测量安全分析报告图象处理

Influence of Tide Models on the Use of Altimetry Data to Research Sea Level Anomaly

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Geo-Spatial Information Science 2007年第2期10卷 100-104页

作者： XU Jun BAO Jingyang LIU Yanchun YU Caixia department of hydrography and cartography Dalian Naval Academy 667 Jiefang Road Dalian 116018 China

A tide model （named DN1.0）, which contains 12 principal constituents over China seas and the Northwest Pacific is estimated by along-track harmonic analysis with TOPEX/Poseidon altimetry data taken from 1993 to 2002. CSR3.0, FES95.2 and DNI.0 are used respectively to detide the data for the time series of sea level anomaly （SLA） in the Yellow Sea, East China Sea, South China Sea and Northwest Pacific. The SLA curves and the power spectral density show that the major components that exist in SLA in China seas arise from the error of the tide models.

关键词： satellite altimetry sea level anomaly tide model tidal aliasing

Morphology and distribution of Pronoctiluca (Dinoflagellata, incertae sedis) in the Pacific Ocean

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Acta Oceanologica Sinica 2013年第4期32卷 71-76页

作者： GóMEZ Fernando department of Biological oceanography Institute of Oceanography University of S o Paulo

The diversity and distribution of Pronoctiluca, a marine dinoflagellate of enigmatic systematic position, was studied in the vicinity of the Kuroshio and Oyashio Currents, the Philippines, Celebes, Sulu and South China Seas, western and central equatorial and southeast Pacific Ocean. The abundance of Pronoctiluca was high- er, with a wide vertical distribution, in eutrophic temperate regions, whereas it was nearly absent in surface waters of oligotrophic tropical regions. Most of the specimens corresponded to P. spinifera. Pronoctiluca pelagica, covered by hyaline layers and with no flagella, is considered as an encysted form. The bipartition was only observed in P. acuta-P, spinifera forms, that together with the occurrence of intermediate forms between P. spinifera and P. pelagica suggest that they may correspond to developmental stages of a single species. Pronoctiluca is essential to understanding the evolutionary history of the alveolates.

关键词： Alveolata basal dinoflagellates Dinophyceae heterotrophic flagellate Noctilucales plankton