共查询到17条相似文献，搜索用时 78 毫秒
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为实现海岸带测量成果陆部要素与海部要素在垂直方向的基准统一,首先建立了一般陆海部要素包括灯塔、灯标等特殊海部要素在垂直方向的基准转换关系;其次构建了高精度的理论最低潮面、海面地形(验潮站平均海面高程)等潮汐数值模型;最后对海岸带垂直基准转换作了精度估算。 研究表明,一般海部要素的垂直基准转换精度优于 35cm,灯塔、灯标等特殊海部要素的垂直基准转换精度优于 45cm。 相似文献
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针对当前海图抽选过程由于缺乏有效的海图抽选算法,而造成抽选效率不高甚至有可能漏选海图的问题,按照海图抽选原则并利用海图比例尺及海图覆盖区域信息,对船舶航行区域进行分级处理,提出了一种基于航行区域分级的海图自动抽选算法,阐述了该算法的基本思路和实现步骤,并通过实验验证了该算法的可行性。 相似文献
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Generalization is a comprehensive process. It is not simply a question of an algorithm, such as simplification, selection, displacement, and so on. Only after geometric shapes and topological properties have been understood fully, can a sound and automated generalization process be possible. This article proposes a new theoretical model for sounding generalization in digital nautical charts. First, with the aid of Delaunay triangulation, a tree structure is introduced for a hierarchical representation of the marine topography. Then, an analytical algorithm for the recognition and the measurement of the marine topography is developed through the use of the tree structure. Finally, all of the techniques mentioned above are integrated into a model for sounding generalization, of which results are illustrated with the aid of several examples. 相似文献
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Generalization is a comprehensive process. It is not simply a question of an algorithm, such as simplification, selection, displacement, and so on. Only after geometric shapes and topological properties have been understood fully, can a sound and automated generalization process be possible. This article proposes a new theoretical model for sounding generalization in digital nautical charts. First, with the aid of Delaunay triangulation, a tree structure is introduced for a hierarchical representation of the marine topography. Then, an analytical algorithm for the recognition and the measurement of the marine topography is developed through the use of the tree structure. Finally, all of the techniques mentioned above are integrated into a model for sounding generalization, of which results are illustrated with the aid of several examples. 相似文献
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港口航道图测量工作量的计算是测绘计划编排和任务管理的基础性工作,一直以来完全采用手工方式操作完成,具有计算工作量大、精度不高、容易出错等缺点。探讨了基于GIS技术的港口航道图测量工作量自动计算系统的主要研究内容,采用GIS技术中的成熟空间操作算法,系统实现了图幅各类多边形的全自动提取、自动裁剪、自动拼接、自动扩展,最终实现工作量的自动计算,从而取代繁琐的人工操作,最大限度实现工作量计算的自动化,改进测绘生产管理效率。 相似文献
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