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901.
902.
“网格化”城市管理系统中城市部件数字化采集方法的探讨 总被引:1,自引:0,他引:1
为了有效地实施"网格化"城市管理,提高城市管理效率,加快城市管理体系的建立,需要全面掌握城市部件的分布和现状情况。城市部件是"网格城市"的基础,高质量的数据采集是提高管理效率的根本。根据具体项目中城市部件采集工作,讨论了有效实用的、又有别于城市测绘的数字化采集方法和步骤,所获取的有效成果证明了该采集方法的可行性。 相似文献
903.
Small‐area patch merging is a common operation in land use data generalization. However, existing research on small‐area patch merging has mainly focused on local compatibility measures, which often lead to area imbalances among land use types from a global perspective. To address the shortcomings of previous studies by resolving local and global concerns simultaneously, this article proposes a merging method that considers both local constraints and the overall area balance. First, a local optimization model that considers three constraints—namely, the areas of neighboring patches, the lengths of shared arcs, and semantic similarity—is established. The areas of small patches are first pre‐allocated. Subsequently, in accordance with an area change threshold for individual land use types, land use types with area changes that exceed this threshold are identified. The patches corresponding to these land use types are subjected to iterative adjustments while considering the overall area balance. Based on their area splitting abilities, the split lines for small‐area patches are determined, and small‐area patches are merged. Finally, actual data from Guangdong Province are used for validation. The experimental results demonstrate that the proposed method is capable of preserving the local compatibility of patches while balancing the overall area associated with each land use type. 相似文献
904.
ABSTRACTThis paper presents a brief overview of the geospatial technologies developed and applied in Chang’e-3 and Chang’e-4 lunar rover missions. Photogrammetric mapping techniques were used to produce topographic products of the landing site with meter level resolution using orbital images before landing, and to produce centimeter-resolution topographic products in near real-time after landing. Visual positioning techniques were used to determine the locations of the two landers using descent images and orbital basemaps immediately after landing. During surface operations, visual-positioning-based rover localization was performed routinely at each waypoint using Navcam images. The topographic analysis and rover localization results directly supported waypoint-to-waypoint path planning, science target selection and scientific investigations. A GIS-based digital cartography system was also developed to support rover teleoperation. 相似文献
905.
Yulin Ding Yuting Wu Qing Zhu Liguo Zhang Qianqian Sun Weixi Wang 《Transactions in GIS》2023,27(3):797-820
Bridges located in mountainous areas are vulnerable to rockfall accidents, posing a threat to bridge engineering construction and operation safety in these regions. Under the coupling effect of complex environments and engineering disturbances, integrated rockfall risk simulation has become increasingly important for canyon bridge structural protection in long-term construction and operation phases. One of the main scientific challenges in rockfall risk simulation is studying the interaction between rockfalls and the topography and engineering environments during consecutive contacts. To systematically simulate the integrated bridge rockfall risk, an integrated construction of multivariable elements coupled with rockfall risk environments and scenarios is required. In this article, we proposed a VGE-based integrated rockfall scenario simulation method that uses the “associated representation—integrated modelling—interactional simulation” core strategy. Our method constructs a virtual rockfall risk environment by fusing multisource data to represent rockfall factors that induce rockfall disasters, hazard-forming environments, and elements at risk. We design rockfall scenarios under different bridge engineering construction conditions and extreme environmental conditions to analyze the interactional rockfall risks. The results demonstrate that our method enables a systematic analysis of the potential integrated rockfall risk, providing realistic reference value for the timely and effective disposal of emergencies, and reducing the harm and losses caused by such emergencies. 相似文献
906.
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908.
WUXiaofang CAIZhongliang WUGuofeng DUQingyun 《地球空间信息科学学报》2003,6(4):27-31
Through analyzing the principle of data sharing in the database system, this paper discusses the principle and method for integrating and sharing GIS data by data engine, introduces a way to achieve the high integration and sharing of GIS data on the basis of VCT in VC , and provides the method for uniting VCT into RDBMS in order to implement a spatial database with object-oriented data model. 相似文献
909.
研究城市雨洪风险问题,对提高城市洪涝灾害监测、预报的准确性,以及促进城市防洪决策制定具有重要的意义。鉴于高精度的城市三维模型可以提供丰富地理信息,便于准确分析淹没情况,本文针对当前城市洪涝模型对地形数据的高敏感性,且雨洪风险评估研究的准确性受限于地形数据精度的问题,提出利用无人机倾斜摄影测量技术重建高精度实景三维模型,并结合GIS的空间分析功能,以淹没深度为关键指标进行研究区的雨洪风险评估。通过提取不同重现期下研究区的淹没深度信息,进行可视化渲染实现三维淹没分析,可以直观地看到研究区的淹没情况,作为暴雨内涝风险管理依据,同时对城市规划布局有一定的参考价值。 相似文献
910.
提出了一种基于深度学习技术的遥感分类方法,它能有效解决中分辨率影像在分类过程中出现的像元混分问题。研究选用2016年5月12日武汉市Landsat 7 ETM+遥感影像,基于GoogleNet模型中的Inception V3网络结构,借助迁移学习方法,构建出遥感分类模型,实现了对武汉市主城区4类典型地物(不透水层、植被、水体和其他用地)的自动分类提取,并将分类结果与传统最大似然分类(ML)结果进行了对比分析。研究表明:基于深度学习方法的遥感影像总体分类精度高达88.33%,Kappa系数为0.834 2,明显优于传统ML方法总体分类精度83%和Kappa系数0.755 0,而且有效抑制了地物在分类过程中出现的像元混分现象。 相似文献