共查询到17条相似文献,搜索用时 125 毫秒
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每天进出美国港口的油轮达数百艘,其他船舶达数千条。这些船舶装载的货物和搭乘的乘客对美国经济十分重要。美国所消耗的石油的一半,对外贸易的90%以上(按重量计)都是由船舶运输的。由此也带来了客、货轮各类事故较为频繁。搁浅、碰撞和触礁等事故占美国海域海上航行事故的大部分,每年造成数10亿美元 相似文献
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电子海图系统将使海上航行发生革命性变革,是自雷达问世以来在改善航行安全方面取得的最大进步。美国国家海洋大气局(NOAA)自80年代初以来一直从事电子海图系统和标准的研究。NOAA工作的成果有电子海图显示与信息系统(ECDIS)及其电子航海图(ENC)的国际标准,最近还通过了光栅显示系统(RCDS)和光栅海图(RNC)标准。 相似文献
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简要分析了海图信息系统的流程、系统结构,提出了海图信息系统在海事管理、航海保障等方面的应用,以及具体应用中存在和应注意的问题。 相似文献
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介绍了中国海事电子海图数据发布现状,结合IHO电子海图数据保护方案(S-63),提出了一种新的电子海图数据自动更新机制。 相似文献
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邓康全 《海洋与海岸带开发》2012,(3):67-69
电子海图和海事雷达是航海的重要助航设备。为提高船舶在航行中的避碰能力,文章提出了电子海图图像与雷达信号的叠加方法。雷达的模拟视频信号、方位信号和触发脉冲,通过数模转换,利用极坐标与直角坐标变换模型和图像匹配,可以在电子海图底图上实时显示雷达捕获到的目标,以提高对船舶周围环境的监控能力。 相似文献
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This article introduces the most advanced form of electronic chart display and information systems (ECDIS) which complies with the performance standards for ECDIS established by the International Maritime Organization (IMO) and International Hydrographic Organization (IHO). It also describes the key features and the important functions of ECDIS, which we developed. This system is different from the productions developed by C-map, Seven-cs, offshore, and others. It is more suitable for China Marine Safety Administration Bureau to manage the navigation marks real-time. Using this system charts were located and accessed rapidly, and displayed smoothly. This article also discusses in ECDIS application system how to dynamically access and desert charts data in a limited memory (limited computer memory and resource). We constructed a tridimensional structure to manage a large amount of charts data. Vertically, according to the scale range, all charts were divided into eight levels, and a data structure called as “Multiple Scale Quad-tree” was constructed. And horizontally, a grid (every unit has a fixed size) was given to a certain scale level. We call this data structure a “Regular Page.” We explore the implementation of such a structure on the worldwide charts management utilizing quad-trees. Then we discuss the future development of ECDIS and its application system in marine agencies in China. 相似文献
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This article introduces the most advanced form of electronic chart display and information systems (ECDIS) which complies with the performance standards for ECDIS established by the International Maritime Organization (IMO) and International Hydrographic Organization (IHO). It also describes the key features and the important functions of ECDIS, which we developed. This system is different from the productions developed by C-map, Seven-cs, offshore, and others. It is more suitable for China Marine Safety Administration Bureau to manage the navigation marks real-time. Using this system charts were located and accessed rapidly, and displayed smoothly. This article also discusses in ECDIS application system how to dynamically access and desert charts data in a limited memory (limited computer memory and resource). We constructed a tridimensional structure to manage a large amount of charts data. Vertically, according to the scale range, all charts were divided into eight levels, and a data structure called as “Multiple Scale Quad-tree” was constructed. And horizontally, a grid (every unit has a fixed size) was given to a certain scale level. We call this data structure a “Regular Page.” We explore the implementation of such a structure on the worldwide charts management utilizing quad-trees. Then we discuss the future development of ECDIS and its application system in marine agencies in China. 相似文献
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建立了一种计算机海图档案系统。系统由海图预处理、海图图库管理和海图应用三个部分组成,采用内部局域网的C/S方式和外部单机方式的双重模式结构,构建成可以对数字海图的多种资料包括矢量和栅格数据进行管理,并提供一定的图档管理、查询和标注功能以辅助海事业务管理的系统。 相似文献
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从语言学层次结构,提出了在电子海图生产中,可以通过语法、语义、语用层次考虑电子海图的空间认知功能,这一模型突破了传统电子海图质检仅关注S-57符合性检查和生产过程检查的缺陷,为电子海图质量控制提供了新的理论体系。 相似文献
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数字地球模式下的电子海图应用 总被引:4,自引:1,他引:4
从数字地球与电子海图的关系入手,讨论了数字地球概念下的电子海图应用模式,给出了应遵循的标准和数据组织方法,探讨了电子海图无缝拼接、无级缩放、通用接口、分层显示、双向查询等功能的实现原理。 相似文献