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城市基础地理数据库是数字城市的重要基础组成部分，本文结合上海基础地理数据库的建库工作给出大型城市基础地理数据库建设中制订数据标准、利用原有数字成果的经验，并介绍相应的数据处理方法。 相似文献
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利用位置签到数据探索城市热点与商圈 总被引：1，自引：0，他引：1
众源地理数据（Crowd Sourcing Geographic Data）是指由大众采集并向大众开放共享的地理空间数据。众源位置签到数据作为众源地理数据的一种,客观真实的反映了大众日常生活行为,包含大量丰富的社会化属性信息。本文提出了一种基于众源位置签到数据的城市热点探测与商圈挖掘方法,首先对位置签到数据时空分布特性进行了研究,设计并提出了众源位置签到数据时空数据库模型;其次,提出了位置签到数据探索性空间分析方法,通过对众源位置签到数据的空间聚类分析,实现基于位置签到数据的商圈热点探测;最后,以武汉市为例,对街旁网截止2011年9月30日的众源位置签到数据进行了城市热点探测与商圈挖掘分析实验,结果表明,基于众源位置签到数据挖掘的武汉市商圈分布与城市规划商圈具有强相关性,可用于城市社会经济发展预测与区域经济规划。 相似文献
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数字城市建设过程中产生"信息孤岛"的原因在于各职能部门对同一地理实体的认知不同,采用了不同的空间数据格式和数据建模方法。为了解决"信息孤岛"问题,在数据库建模过程中采用大型关系型数据库以支持海量数据的共建共享,尝试用组份拓扑学与地理定位理论从数学层面上探讨数据建模问题。 相似文献
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地图数据库图形输出中要素关系处理 总被引：3，自引：2，他引：3
本文提出了利用地图数据库的检索功能，建立要素图形输出的定量优先级、地理要素图形大小，及基于地图数据库的图形冲突位置的探测方法，并将要素图形输出中的关系划分为五种进行分别处理。 相似文献
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基于岭估计的粗差探测 总被引：2，自引：0，他引：2
针对测量平差Gauss-Markov模型中法矩阵的病态性和观测值的粗差同时存在问题,把岭估计和粗差探测两者的优点结合起来提出了基于岭估计的粗差探测方法.该方法把岭估计看成具有伪观测值的最小二乘估计,然后运用基于最小二乘估计的粗差探测技术探讨岭估计意义下的奇异点,并给出奇异点的检验统计量和判断方法.数值实验表明,新方法在克服病态性的同时能够有效地识别出可疑(可能含粗差)的观测值. 相似文献
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A Multiscale Approach for Spatio-Temporal Outlier Detection 总被引：1，自引：0，他引：1
A spatial outlier is a spatially referenced object whose thematic attribute values are significantly different from those of other spatially referenced objects in its spatial neighborhood. It represents an object that is significantly different from its neighbourhoods even though it may not be significantly different from the entire population. Here we extend this concept to the spatio‐temporal domain and define a spatial‐temporal outlier (ST‐outlier) to be a spatial‐temporal object whose thematic attribute values are significantly different from those of other spatially and temporally referenced objects in its spatial or/and temporal neighbourhoods. Identification of ST‐outliers can lead to the discovery of unexpected, interesting, and implicit knowledge, such as local instability or deformation. Many methods have been recently proposed to detect spatial outliers, but how to detect the temporal outliers or spatial‐temporal outliers has been seldom discussed. In this paper we propose a multiscale approach to detect ST‐outliers by evaluating the change between consecutive spatial and temporal scales. A four‐step procedure consisting of classification, aggregation, comparison and verification is put forward to address the semantic and dynamic properties of geographic phenomena for ST‐outlier detection. The effectiveness of the approach is illustrated by a practical coastal geomorphic study. 相似文献
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The Integration of Geographic Visualization with Knowledge Discovery in Databases and Geocomputation
《制图学和地理信息科学》2013,40(1):29-44
This paper details the research agenda of the International Cartographic Association Commission on Visualization: Working Group on Database-Visualization Links. The paper stresses the need for the closer integration of three largely disparate technologies: geographic visualization, knowledge discovery in databases, and geocomputation. The introduction explains the meaning behind these terms, the ethos behind their practice, and their connections within the broad realm of knowledge construction activities. The state of the art is then described for different approaches to knowledge construction, concentrating where possible on visual and geographically oriented methods. From these sections, a research agenda is synthesized in the form of three sets of research questions addressing: (1) visual approaches to data mining; (2) visual support for knowledge construction and geocomputation; and (3) databases and data models that must be satisfied to make visually-led knowledge construction a reality in the geographic realm. Conclusions relate this agenda to issues of (1) data, (2) geographic knowledge, and (3) the visualization environment and pose significant challenges to the way we currently represent geographic information and knowledge within computational systems. 相似文献
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当前各地国土部门建立并投入使用的GIS数据库,大多采用独立、分散的数据库管理模式。该模式的缺陷在于:上下级数据库完全独立运行,无法实施有效的数据同步;导致数据库投入使用时间越长,上下级间的数据差异越大。传统的数据同步方式因功能限制而无法满足GIS数据同步的需求。Geodatabase双向复制能够在不同数据库平台多个地理数据库间实现数据双向同步,可以很好地解决上述问题。基于阳新县土地利用数据库建立分布式地理数据库,利用Geodatabase复制技术实现了同一数据库平台下多个地理数据库间的数据双向同步。 相似文献
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Addresses occupy a niche location within the landscape of textual data, due to the positional importance carried by every word, and the geographic scope it refers to. The task of matching addresses happens every day and is present in various fields such as mail redirection, entity resolution, etc. Our work defines, and formalizes a framework to generate matching and mismatching pairs of addresses in the English language, and use it to evaluate various methods to automatically perform address matching. These methods vary widely from distance-based approaches to deep learning models. By studying the Precision, Recall, and Accuracy metrics of these approaches, we obtain an understanding of the best suited method for this setting of the address matching task. 相似文献
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从GIS数据库中挖掘空间离群点的一种高效算法 总被引：3，自引：0，他引：3
根据GIS的空间特性，借鉴已有的定义和概念，定义了空间离群点是和在其非空间属性邻域内其他空间对象在空间位置上差异十分显著的空间对象，并设计了SOD算法。实验结果验证了SOD算法的有效性和优越性，给出了从GIS数据库中挖掘空间离群点的一般步骤。 相似文献
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基础地理信息数据库是我国要建立的四大数据库中的重要内容,各省均相继开展或完成了省级基础地理信息数据库的建设。数据库建成后,如何高效和安全地使用数据库,广泛服务于社会,是当前面临的重要问题。本文结合数据库的建设现状,从实际需求出发,在实践中归纳了基础地理信息数据库目前及未来应用的设想。 相似文献
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Quality Assessment of the French OpenStreetMap Dataset 总被引：9，自引：1，他引：8
The concept of Volunteered Geographic Information (VGI) has recently emerged from the new Web 2.0 technologies. The OpenStreetMap project is currently the most significant example of a system based on VGI. It aims at producing free vector geographic databases using contributions from Internet users. Spatial data quality becomes a key consideration in this context of freely downloadable geographic databases. This article studies the quality of French OpenStreetMap data. It extends the work of Haklay to France, provides a larger set of spatial data quality element assessments (i.e. geometric, attribute, semantic and temporal accuracy, logical consistency, completeness, lineage, and usage), and uses different methods of quality control. The outcome of the study raises questions such as the heterogeneity of processes, scales of production, and the compliance to standardized and accepted specifications. In order to improve data quality, a balance has to be struck between the contributors' freedom and their respect of specifications. The development of appropriate solutions to provide this balance is an important research issue in the domain of user‐generated content. 相似文献
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S. Fleming T. Jordan M. Madden E.L. Usery R. Welch 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(2):213-222
In order to successfully support current and future US military operations in coastal zones, geospatial information must be rapidly integrated and analyzed to meet ongoing force structure evolution and new mission directives. Coastal zones in a military-operational environment are complex regions that include sea, land and air features that demand high-volume databases of extreme detail within relatively narrow geographic corridors. Static products in the form of analog maps at varying scales traditionally have been used by military commanders and their operational planners. The rapidly changing battlefield of 21st Century warfare, however, demands dynamic mapping solutions. Commercial geographic information system (GIS) software for military-specific applications is now being developed and employed with digital databases to provide customized digital maps of variable scale, content and symbolization tailored to unique demands of military units. Research conducted by the Center for Remote Sensing and Mapping Science at the University of Georgia demonstrated the utility of GIS-based analysis and digital map creation when developing large-scale (1:10,000) products from littoral warfare databases. The methodology employed–selection of data sources (including high resolution commercial images and Lidar), establishment of analysis/modeling parameters, conduct of vehicle mobility analysis, development of models and generation of products (such as a continuous sea–land DEM and geo-visualization of changing shorelines with tidal levels)–is discussed. Based on observations and identified needs from the National Geospatial-Intelligence Agency, formerly the National Imagery and Mapping Agency, and the Department of Defense, prototype GIS models for military operations in sea, land and air environments were created from multiple data sets of a study area at US Marine Corps Base Camp Lejeune, North Carolina. Results of these models, along with methodologies for developing large-scale littoral warfare databases, aid the National Geospatial-Intelligence Agency in meeting littoral warfare analysis, modeling and map generation requirements for US military organizations. 相似文献
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扫描匹配是移动机器人定位和环境构图的关键问题之一,通过计算使相邻扫描重叠度最大的最优变换,从而估算相邻时刻的运动量。ICP算法是目前应用最广泛的扫描匹配算法,针对其对离群扫描点和稀疏扫描点敏感的问题,文中提出一种基于连通格序列的方法对扫描数据进行预处理,从而为扫描匹配提供较为理想的输入条件。此外,针对对应关系中一对多和对应距离极端大的问题,文中通过建立唯一对应,并基于四分位数法计算对应距离的上截断点进行剔除,从而避免建立一对多对应,并减少距离极端大的对应。实验结果表明,文中方法能够剔除扫描中的离群点与稀疏点,并改善ICP算法在实际应用中的扫描匹配表现。 相似文献