共查询到19条相似文献,搜索用时 796 毫秒
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面向对象方法在地理空间信息元数据标准研发中的应用研究 总被引:4,自引:0,他引:4
介绍了地理空间信息元数据和面向对象方法的基本概念,分析了地理空间信息元数据所具有的面向对象特性,以国标《地理信息元数据》采用面向对象建模语言UML对元数据模式进行表达为基础,提出了采用面向对象方法研发我国行业、领域地理空间信息元数据标准的思路,以元数据类为基本单元构造了具体的实施方法,并在《水利地理空间信息元数据标准》的研发过程中实施了该方法,验证了面向对象研发地理空间信息元数据标准的科学性和可行性。 相似文献
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基于JSP的空间元数据发布系统的设计与实现 总被引:3,自引:0,他引:3
首先介绍元数据、地理空间元数据和空间元数据发布系统的相关概念,并讨论在互联网时代元数据发布系统研究的必要性;其次论述发布系统的实现技术、体系结构及其运行流程;最后在JSP环境中实现了一个基于水利地理空间元数据标准的空间元数据发布系统. 相似文献
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地理元数据技术系统的设计与实现 总被引:30,自引:0,他引:30
介绍了地理元数据的概念,类型,标准与应用模式 ,以吉林省农业信息元数据系统为例,探讨了元数据技术系统的实现方法,并提出地理元数据库设计,元数据登录系统,检查系统和系统等关键技术问题的解决方案。 相似文献
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对数据仓库、元数据等进行了简单介绍,并针对地理信息系统中元数据的作用、内容进行了阐述,在此基础上,对地理信息系统中元数据的管理方法提出了建议。 相似文献
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地理元数据技术系统的设计与实现 总被引:2,自引:0,他引:2
介绍了地理元数据的概念、类型、标准与应用模式,以吉林省农业信息网元数据系统为例,探讨了元数据技术系统的实现方法,并提出地理元数据库设计、元数据登录系统、检查系统和查询系统等关键技术问题的解决方案。 相似文献
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本文探讨了建立空间元数据管理系统所涉及的一些标准和技术,重点介绍了ArcCatalog中的元数据管理和XML技术及其在元数据系统中的作用.针对ArcCatalog空间数据管理的特点及开放的扩展机制,深入讨论了用户定制的元数据编辑器开发的步骤、主要技术等,并设计开发出一种基于XML的空间数据元数据编辑器,为地球空间元数据... 相似文献
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对数据仓库、元数据等进行了简单介绍,并针对地理信息系统中元数据的作用、内容进行了阐述,在此基础上,对地理信息系统中元数据的管理方法提出了建议,供同行参考。 相似文献
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地理资源是建设"一张图"的基础,元数据是资源与用户之间重要的桥梁。本文介绍了地理资源元数据的概念、标准和作用,结合对一张图系统的需求情况,初步设计了元数据的内容,并强调了空间元数据的一些关键要求。 相似文献
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战场地理空间信息可视化系统设计与研究 总被引:1,自引:0,他引:1
对当前流行的3DGIS系统进行了介绍,并研究提出了采用面向对象的方法来表达3D场景中的空间数据,基于栅格金字塔模型来组织和管理地形数据,基于视点相关的地形LoD方法实现了大范围漫游,基于参数化3D建模方法和矢量地物LoD来实现地物数据的建模和可视化的方法,设计和构建西北地区战场地理空间信息可视化系统(3DMGIS)。 相似文献
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G. Blaha 《Journal of Geodesy》1977,51(1):33-45
The short arc adjustment mode makes a determination of the geoid surface possible without the requirement of highly precise
reference orbits. In this mode, the state vector components are subject to adjustment and represent in fact a set of independent
weighted parameters. In a most elementary approach, the radial distance to a satellite point is differentiated with respect
to these parameters and a radial distance to the geoid (r) is differentiated with respect to the earth potential coefficients.
The observed satellite altimetry value (H) is approximately equal to the difference between these two radial distances. In
the present study, a correction is introduced that makes it possible to express the mathematical model for H as accurately
as practicable, good to a few centimeters. With regard to the partial differentiation, it is argued that r, in addition to
being differentiated with respect to the potential coefficients, has to be differentiated also with respect to the state vector
components. This gives rise to a second type of correction. It is shown that for most practical purposes, the ellipsoidal
approximation to the geoid used to compute the above two kinds of corrections is satisfactory. The final results indicate
that actual computation of these corrections is a very simple matter; an eventual upgrading of satellite altimetry computer
programs can thus be accomplished with almost no additional effort. A practical benefit of the presented analysis is faster
convergence in the adjustment which, in some cases, may remove the need for iterated solutions altogether. 相似文献
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In order to understand the nature of the urban climate, predict the effects of urbanization, or attempt to ameliorate some of the negative hydroclimatic effects of urbanization, it is necessary to have a good understanding of the role and significance of the urban surface. This paper presents a methodology which uses GIS to represent the characteristics and morphology of the urban surface, which can be used to describe a site objectively, model fluxes, or ensure spatial consistency between measured and modelled data, all of which can vary through time. The methodology is illustrated with respect to Chicago, Illinois. Surface data collected at three spatial scales were used to construct a georeferenced database which was linked to an objective, dynamic accessing system. Spatial variability of surface cover, derived hydroclimatic attributes, and modelled fluxes associated with changes in the urban environment are used to illustrate potential applications of the approach. 相似文献
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阐述了GIS网络分析中不确定性选址问题的基本模型及特性。从问题的定义可知其为NP完备类问题。推导了最优解在紧条件的下界算法,并结合广义Powell算法及遗传算法,提出了不确定性选址问题的混合遗传算法,实验证明,在最优解的品质和收敛速度上都达到了比较好的效果。同时,实验的结果从另一个角度证明,如果兼顾收敛速度和解的品质这两个指标,单纯的遗传算法未必比其他搜索算法更优越,采用一些局部搜索性能较好的算法结合遗传算法,可以从两方面改善求解效果。 相似文献
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Mangrove forests grow in the estuaries of 124 tropical countries around the world. Because in-situ monitoring of mangroves is difficult and time-consuming, remote sensing technologies are commonly used to monitor these ecosystems. Landsat satellites have provided regular and systematic images of mangrove ecosystems for over 30 years, yet researchers often cite budget and infrastructure constraints to justify the underuse this resource. Since 2001, over 50 studies have used Landsat or ASTER imagery for mangrove monitoring, and most focus on the spatial extent of mangroves, rarely using more than five images. Even after the Landsat archive was made free for public use, few studies used more than five images, despite the clear advantages of using more images (e.g. lower signal-to-noise ratios). The main argument of this paper is that, with freely available imagery and high performance computing facilities around the world, it is up to researchers to acquire the necessary programming skills to use these resources. Programming skills allow researchers to automate repetitive and time-consuming tasks, such as image acquisition and processing, consequently reducing up to 60% of the time dedicated to these activities. These skills also help scientists to review and re-use algorithms, hence making mangrove research more agile. This paper contributes to the debate on why scientists need to learn to program, not only to challenge prevailing approaches to mangrove research, but also to expand the temporal and spatial extents that are commonly used for mangrove research. 相似文献
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智慧农场在线综合服务平台系统的研究与设计 总被引:1,自引:0,他引:1
结合农场发展实际情况,提出智慧农场在线综合服务平台建设指导思想、建设原则、核心建设内容及建设与运行模式,剖析其实际的功能与性能需求。针对智慧农场建设内容,综合旅游、农田、社区、微信平台等方面,提出能适应功能需求不断变化的智慧农场在线综合服务平台系统架构,为智慧农场建设提供新的思路,以期为智慧农场信息服务标准化建设提供指导。 相似文献
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测绘成果是重要的信息资源,总结了现有测绘成果管理的国家政策法规.对北京市和兄弟省市在政策法规与标准建设、机构建设、测绘成果的汇交与发布进行了对比分析.提出进一步完善测绘成果管理政策法规;成立专门的测绘成果管理机构,加强对测绘成果汇交情况的监管;建立与测绘成果汇交有关的数据标准;加大经费投入,保障测绘成果管理工作的顺利进行;集成整合规划监督测量成果,降低测绘成果生产成本;研发相关网站,促进测绘成果分发共享,大力开展测绘产品增值服务. 相似文献
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“数字鸿沟”与地球信息科学的应对 总被引:2,自引:1,他引:2
2003年上半年连续出现的全球性突发事件,是对我国的严峻考验。面对严峻复杂的世界形势,地球信息科学可以大有作为,如建设各类型的地理信息系统,以增强应变能力,制定长远规划,加强基础研究和数据储备,将地球信息科学的先进技术和成果应用于国家应对突发事件和政府决策,提出强强联合,共同攻克难关。 相似文献