基于ArcGIS的国家台网地震速报地名查询辅助系统设计与实现     

郭凯  侯建民  闫恩辉 《震灾防御技术》2015,10(4):913-924

基于国家台网地震速报的实际工作需求,针对国家台网在全球地震速报中缺乏专门的地名查询系统,通过对国家台网实时、人机交互处理子系统和全国速报信息交换平台(EQIM系统)的相关协议和数据接口进行研究,并结合地震速报相关规定中对地名的要求,基于地理信息系统Arc GIS提供的Arc GIS Engine(AE)组件技术,采用Visual.Net开发平台和COM组件技术,来实现获取地震地名信息的功能,开发设计一套用于国家台网地震速报的地名查询辅助系统,希望可以有效提高国家台网地震速报的效率和准确度。  相似文献   

求解制图区域的地图图幅编号的算法研究     

吴曜宏  乔俊军  胡冯伟 《地理信息世界》2017,24(4)

基于地理格网理论,从点、线、面三个方面,提出了归原法、斜率分段-同异侧判别法和投影反算-图廓内外判别法,这些算法可准确映射各种投影后制图区域所对应的基础地理信息数据范围,实现了制图范围内地理信息数据所属地图图幅编号的可视化查询。  相似文献   

MODIS影像的局地云量信息元数据提取算法与应用     

钟洪麟  施润和  曲培青  张慧芳  高炜 《地球信息科学学报》2010,12(4):587-592

云对于光学遥感影像质量及其反演地表参数精度有着重要影响,且其作为时空多变要素之一,在一定程度上制约了光学遥感影像的应用。对于具有2 330km的大扫描幅宽MODIS影像而言,现有的元数据标准仅能反映影像的总体云量,而无法反映云的空间分布状况,限制了MODIS数据的局地研究和应用。本文在现有遥感影像元数据标准的基础上,提出了新的元数据项--局地云量,用于反映云在条带影像中的空间分布状况,并实现在MODIS二级云掩膜条带产品(MOD35)中针对特定区域的局地云量信息提取算法。经验证,本算法能较快速和准确地提取省级行政区的局地云量信息,并可根据用户的需求进一步推广到任意指定的多边形区域,为MODIS数据在局地研究和应用提供了便利。  相似文献   

二维空间关系定性表达模型的研究     

唐雪华  孟令奎  秦昆 《地理空间信息》2005,3(5):17-20

通过对几种典型的定性表达模型的分析及比较,论述了单一模型实现空间查询所存在的局限,提出利用组合模型来表达空间关系的方法。最后结合空间查询中的实例,通过介绍如何同时运用二值拓扑关系模型和符号空间索引模型来实现同时包含拓扑关系和方向关系的复杂空间查询来说明这种方法。  相似文献   

GIS and remote sensing integration for environmental applications     

J. C. Hinton 《International journal of geographical information science》2013,27(7):877-890

Abstract

The combined use of remotely-sensed images and vector GIS data has received considerable interest in recent years. This review article discusses the historical move towards closer integration of remote sensing and GIS technologies and the requirements of integrated software systems to enable remotely-sensed data to be combined with vector datasets for maximum effect. The benefits of integration to users of both GIS and remote sensing for environmental applications are reviewed and some thoughts are given on terminology and future directions in this field.  相似文献   

Modeling uncertainty of moving objects on road networks via space–time prisms     

Bart Kuijpers 《International journal of geographical information science》2013,27(9):1095-1117

Moving objects produce trajectories, which are typically observed in a finite sample of time‐stamped locations. Between sample points, we are uncertain about the moving objects's location. When we assume extra information about an object, for instance, a (possibly location‐dependent) speed limit, we can use space–time prisms to model the uncertainty of an object's location.

Until now, space–time prisms have been studied for unconstrained movement in the 2D plane. In this paper, we study space–time prisms for objects that are constrained to travel on a road network. Movement on a road network can be viewed as essentially one‐dimensional. We describe the geometry of a space–time prism on a road network and give an algorithm to compute and visualize space–time prisms. For experiments and illustration, we have implemented this algorithm in MATHEMATICA.

Furthermore, we study the alibi query, which asks whether two moving objects could have possibly met or not. This comes down to deciding if the chains of space–time prisms produced by these moving objects intersect. We give an efficient algorithm to answer the alibi query for moving objects on a road network. This algorithm also determines where and when two moving objects may have met.  相似文献   

对1970云南通海地震参数、伤亡、公布形式质疑的商榷          下载免费PDF全文

张津  郭安宁  张向红  任栋  张炜超 《地震工程学报》2013,35(S1):173-177

1970云南通海大地震造成15 621人丧生,是1949年建国以来仅次于唐山地震与汶川地震死亡人数最多的地震。由于在特定历史时期发生的地震,因而在社会上对这个地震的情况产生了质疑,质疑最终的结果是贬低本次地震的部分工作,这与过去所做的结论有冲突,就此,本文就质疑的地名、震级、伤亡人数及公布方式等相关问题,从文献与档案资料进行调查研究和分析,回复质疑并对历史真实情况及事件发生的原委得出结论。  相似文献   

基于语义类型本体的地名组配查询     

陈健  张斌  梁汝鹏 《地理空间信息》2013,(3):126-127

地名查询方式多种多样,但它们都没有考虑地名语义类型因素,而语义类型恰恰是地名信息中相当重要的一部分。以地名语义分类为基础,构建了地名语义类型本体模型,并以郑州市为例进行了地名组配查询实验。结果表明,该方式对于检索地名的相关信息具有较好的辅助作用,为地名查询与检索作了有益的补充。  相似文献   

GQL: Extending Xquery to query GML documents     

Guan Jihong 《地球空间信息科学学报》2013,16(2):118-126

GML is becoming the de facto standard for electronic data exchange among the applications of Web and distributed geographic information systems. However, the conventional query languages (e.g. SQL and its extended versions) are not suitable for direct querying and updating of GML documents. Even the effective approaches working well with XML could not guarantee good results when applied to GML documents. Although XQuery is a powerful standard query language for XML, it is not proposed for queryings spatial features, which constitute the most important components in GML documents. We proposes GQL, a query language specification to support spatial queries over GML documents by extending XQuery. The data model, algebra, and formal semantics as well as various spatial functions and operations of GQL are presented in detail.  相似文献   

海量、异构矿业权核查数据的查询与优化     

陈苗  王永志  王慧 《测绘软科学研究》2011,(5):26-28,41

矿业权核查单个矿业权成果数据具有文件小、数量多、异构、多源等特点,对从海量、异构核查成果数据中快速查询并提取数据提出了挑战。本文探讨并建立了科学合理的数据模型．并提出综合应用表分区、存储过程、优化查询语句等数据库技术,有效提高了核查成果数据的访问与提取效率,为相同或类似应用需求提供了参考。  相似文献