共查询到19条相似文献,搜索用时 62 毫秒
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道路数据缩编更新的自动综合方法研究 总被引:1,自引:0,他引:1
缩编更新是当前GIS多尺度数据库更新的重要技术途径之一。针对我国国家1∶5万数据库更新工程的实际需求,研究分析了用较大比例尺新道路数据缩编更新较小比例尺道路数据的总体思路,提出了基于网眼密度的道路选取和顾及层次分析的道路匹配方法,实现了道路数据缩编更新的自动综合处理,并在1∶5万数据更新实践中进行了实验验证。 相似文献
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将等高线看作是由高程点以特定形式组织得到的空间三维线段,采用3维Douglas-Peucker算法从三维空间提取等高线上的主要特征点。根据等高线数据特点,对该算法进行等高线综合的几种方案进行实验讨论。实验结果和运算速度表明,采用3维Douglas-Peucker算法综合等高线具有广阔的研究前景。 相似文献
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以“天地图·甘肃”道路数据为研究对象,针对甘肃省天地图道路数据融合效率低的问题,对道路数据融合关键技术进行分析,利用道路网匹配技术实现甘肃省天地图道路变化检测与更新的技术优化,相比传统的处理方式,可减少2/3的人工工作量。 相似文献
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在数字环境下进行等高线综合是制图综合领域中的热点问题.将3维Douglas-Peucker算法应用于等高线综合,是从真3维的角度提取等高线上的特征点.首先根据等高线上高程点的空间分布特征.提出采用空间线规则排序方法组织空间点;引入了全局孤独指数解决综合过程中等高线之间的空间跳跃问题;然后通过空间内插引绘综合后DEM的等高线,从而实现等高线的自动综合.初步实验表明,采用3维Douglas-Peucker算法的等高线综合,从全局上保持了主要地貌形态并抑制了破碎的微地貌特征,具有良好的综合质量和制图效果. 相似文献
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目前三维Douglas-Peucker(3D_DP)算法主要应用于单一类型的DEM综合。本文引入"弯曲调节指数"来改进3D_DP算法,提出了一种三维空间河网要素与DEM综合的新方法,即将河网线矢量提取成三维离散点数据集(增加高程属性),与DEM三维离散点数据集合并,在河网层次化选取基础上,利用改进的3D_DP算法对合并数据集进行综合操作。通过试验结果的对比和分析表明,该方法通过弯曲调节指数的调节使河流自身所具有的弯曲形态与地形的主要特征得以同时保留,试验效果良好,实现了三维空间河网要素与DEM数据在同一简化因子作用下的综合,提升了地图综合的质量。 相似文献
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《International Journal of Digital Earth》2013,6(2):133-153
Abstract When road symbols are shown in a size proportionate to the reduced scale, several problems of legibility may arise concerning the urban blocks. By the method proposed in this paper, in order to overcome these problems, urban block areas are enlarged through amalgamation and the intervening roads in the amalgams are eliminated. This method includes two new approaches for computation of threshold used in determination of important roads based on the connectivity measure, and for definition of minimum block space and area requirements based on graphic limits. A block life cycle was designed for amalgamation of blocks. For the amalgamation process, a new algorithm was developed. The experimental testing indicates that important roads and the roads surrounding the urban area have been preserved. A simpler and more legible road network has been acquired. This method can be described as a more holistic approach as the buildings are taken into account. The problems arising in the experimental testing indicate that the cartographic selection/elimination process is not sufficient by itself for road network generalization, which can be assumed as one of the integral parts of Digital Earth. As well as the selection/elimination, processes such as displacement and caricaturizing are also needed. 相似文献
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道路网自动综合是GIS研究的重要基础理论问题。顾及道路重要性对路网制图综合的影响,采用基于对偶拓扑的复杂网络理论构建城市路网对偶拓扑模型,并基于该路网模型建立路段重要度评价方法,进而提出一种基于路段重要度评价的路网自动制图综合方法。实验表明,该方法能够有效地完成不同比例尺下路网的自动综合。 相似文献
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现有的曲线化简算法不能很好地化简具有交叉路口的道路曲线,针对这一问题提出一种基于交叉点的道路曲线化简算法。算法分为预化简和修正化简两个阶段:首先识别并得到曲线上的分段点,利用相邻的分段点作为道格拉斯-普克算法的首尾点对曲线进行化简,得到预化简的结果;然后对于交叉点引入偏差阈值ε,通过判断道路曲线交叉点与化简后交叉点的距离与偏差精度ε的大小关系来确定该交叉点的化简与保留,如果保留或者化简后的道路曲线没有交叉点那么将原交叉点作为分段点对此段曲线进行重新化简。理论分析与实验结果表明,文中算法能够有针对性地保留或化简道路交叉点以及保持曲线化简后的形态特征。 相似文献
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This paper proposes an algorithm for road density analysis based on skeleton partitioning. Road density provides metric and
statistical information about overall road distribution at the macro level. Existing measurements of road density based on
grid method, fractal geometry and mesh density are reviewed, and a new method for computing road density based on skeleton
partitioning is proposed. Experiments illustrate that road density based on skeleton partitioning may reveal the overall road
distribution. The proposed measurement is further tested against road maps at 1:10k scale and their generalized version at
1:50k scale. By comparing the deletion percentage within different density interval, a road density threshold can be found,
which indicate the need for further operations during generalization. Proposed road density may be used to examine the quality
of road generalization, to explore the variation of road network through temporal and spatial changes, and it also has future
usage in urban planning, transportation and estates evaluation practice.
Supported by the National 863 Program of China(No.2007AA12Z225), the Natural Science Foundation of China(No.40771168). 相似文献
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Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a concrete experiment while maintaining topological consistency of the road network between the original and the schematic map. 相似文献
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Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map 相似文献