共查询到20条相似文献，搜索用时 93 毫秒
1.
2.
分布式网络环境下地理信息元数据框架研究 总被引：4，自引：0，他引：4
在研究现有的地理信息元数据标准定义的元数据框架厦其管理模式的基础上，提出了一种可操作的、面向对象的元数据内容框架和分级的、基于地图的元数据组织方式，方便了分布式网络环境下地理信息服务的检索、查找和获取。 相似文献
4.
5.
陈珂;温家洪;俞立中 《东北测绘》2013,(4):4-8
元数据标准是数据库的一个重要组成部分,对自然灾害研究而言,涉及全球范围的历史灾情、时空信息等海量数据,在形成灾害数据库的过程中,离不开元数据标准的设计与构建。本文介绍了元数据与元数据标准的基本概念、特征以及作用等内容,提出了自然灾害元数据标准的设计思路,即以提高自然灾害数据库的建库质量,增强数据的使用效率,促进数据共享为目标,遵循稳定性与科学性、简单性与准确性、互操作性与易转换性、一致性与可扩展性等原则,实现描述评价、查询检索、管理维护、交换共享等功能。在此基础上,完成了自然灾害元数据标准的构建,共包含六大实体,33个元数据元素,36个元数据子元素。对于每一个元数据元素或子元素,均有九个属性对其加以限制和说明。该元数据标准已经应用于长三角地区自然灾害损失数据库的开发,为自然灾害数据管理和数据库建设提供了依据,是实现自然灾害数据共享的重要途径,也可以作为其它学科领域制定元数据标准的参考。 相似文献
6.
A Sensor Web registry acts as a broker in a service‐oriented environment to publish and discover Sensor Web resources (e.g. sensors, sensor services, observations, and alerts). The Catalogue Service for the Web (CSW) developed by the Open Geospatial Consortium (OGC) defines a standard interface and protocol for publishing and discovering geospatial resources. This article adopts the CSW for the development of a Sensor Web registry. Metadata for Sensor Web resources are registered into the catalogue information model – the ebXML Registry Information Model (ebRIM). In the Sensor Web environment, sensor observations can be available in real‐time or near‐real‐time, and thus metadata registered in CSW need to be updated frequently. This article proposes an incremental harvesting approach, which can harvest the updated metadata efficiently. A prototypical implementation is provided to demonstrate the applicability of the approach. 相似文献
7.
8.
综合省情地理信息系统空间数据元数据设计研究 总被引：13，自引：0，他引：13
综合省情地理信息系统的建立与运行需要元数据的支持，在分别对现有元数据标准和综合省情地理信息系统特点进行分析的基础上，指出了使用元数据的优点，提出了综合省情地理信息空间数据元数据的内容，以提高系统查询检索的速度和系统分析效率为主要目的，对元数据的存储采用了一种以数据库为基础的新的存储模式，以关系表格来管理元数据，建立元数据库。元数据库的管理以图形数据的管理为基础，二者必须协调进行。 相似文献
9.
Creating a conceptual framework to improve the re‐usability of open geographic data in cities 
下载免费PDF全文
下载免费PDF全文 Fernando Benitez‐Paez Alexis Comber Sergio Trilles Joaquin Huerta 《Transactions in GIS》2018,22(3):806-822
Open data has a profound effect on the working environment within which information is created and shared at all levels. At the local government level, open data initiatives have resulted in higher transparency in policy, a greater engagement between decision‐makers and citizens, and have changed the culture about how data analysis and evidence are used to support local governance. This article, based on data collected through an on‐line survey, participatory workshops with data user communities in four cities (in Colombia and Spain), and interviews with Valencia good‐government office, identifies four elements for a conceptual framework to improve the re‐usability of open geographic data in cities. The essential elements defined in this research are the definition of data user communities and their needs, the creation of the community of reuse, user‐focused metadata, and reuse‐focused legal terms. The definition of these indicators provides a framework for authorities to re‐shape their current open data strategy to include data user requirements. At the end of this article, a roadmap for future research and implementation is presented, considering some reflections on the conceptual framework. 相似文献
10.
11.
This survey article describes previous research addressing text‐based document geocoding, i.e. the task of predicting the geospatial coordinates of latitude and longitude, that best correspond to an entire document, based on its textual contents. We describe (1) early document geocoding systems that use heuristics over place names mentioned in the text (e.g. names of cities and states), (2) probabilistic language modeling approaches, where generative models are built for different regions in the world (usually considering a discretization based on a rectangular grid) from the words occurring in a set of georeferenced training documents, which are then used to predict per‐region probabilities for previously unseen test documents, (3) combinations of different models and heuristics, including clustering procedures, feature selection approaches, and/or language models built from different sources, and (4) recent approaches based on discriminative classification models. 相似文献
12.
13.
In a disaster aftermath in places lacking geospatial preparedness, the United Nations Office for the Coordination of Humanitarian Affairs creates a framework for cooperation with the Coordinated Data Scramble initiative, where Information Management Officers (IMOs) from different organizations work together in supporting the coordination of humanitarian aid. The perspective of these IMOs has been considered to identify the factors influencing the use of GIS in this context. The results show the requirement for a geodata management strategy, including geodata gathering, maintenance, and decision‐making processes based on those geodata. Geodata should be reliable and up‐to‐date. It requires consistent and useful metadata and the possibility of contacting the geodata source. Security and political issues limit information sharing. In this context, OpenStreetMap is often used as a source of information. Therefore, improving OpenStreetMap improves geospatial preparedness. Nevertheless, the use of this open platform highlights issues related to information privacy. 相似文献
14.
15.
数字地球建设中的地理空间Metadata研究 总被引：2，自引：0，他引：2
为解决数字地球建设中现有海量地理空间信息的共建共享,有效管理和利用,结合国际地理空间Metadata标准规范,对数字地球建设中所需的地理空间Metadata的定义,作用,分类,内容,实现模型与实例及其应用进行详细研究和设计,提出用于数字地球建设的地理空间Metadata网络管理系统解决方案,并设计实现了原型系统,为数字地球建设中现有海量地理空间信息的有效管理和共建共享提供了理论基础和切实可行的技术支撑。对国家空间信息基础设施建设和数字地球建设具有重要的推动作用和深远的社会意义。 相似文献
16.
17.
国土资源数据集成管理体系是连接诸中心综合信息库、各分节点区域信息库的分布式空间信息集成管理系统,它主要在分布式、多源异构的国土资源数据环境下提供数据汇聚、数据集成、数据发现、数据访问和数据服务等功能,为各类用户和应用系统提供广泛有效的数据共享和交换服务。针对国土资源数据具有的多源、多级服务等需求特征,本文分析了集成模式,应用服务结构和服务请求消息流程与协议等技术,以期对分布式网络环境下的国土资源数据一体化集成和动态服务提供支撑。 相似文献
18.
一种数据网格的元数据分类管理机制研究 总被引：2，自引：0，他引：2
网格环境下数据发现和访问的关键问题是应用元数据管理和拷贝元数据管理，针对这一问题，提出了一种元数据分类管理机制。该机制定义了数据模型和应用元数据模式，采用了分类存储的方式对不同的元数据进行管理，并设计了一个基于向导的查询智能体。 相似文献
19.
Nowadays, NASA is producing several terabytes Moderate Resolution Imaging Spectroradiometer (MODIS) data everyday; how to
find the data with criteria, such as specific times, locations, and scales using an international standard becomes more and
more important. In this paper, a service-oriented architecture for use of the integration Earth Observation System Clearing-HOuse
(ECHO) with the Open Geospatial Consortium (OGC) Catalogue Service—Web profile (CSW) is put forward. The architecture consists
of three roles: a service requester (the user), a service provider (the ECHO metadata server), and a service broker (the GeoNetwork
CSW and MODIS registry service middleware). The core component-MODIS registry service middleware includes three components:
metadata fetcher, metadata transformer, and metadata register. The metadata fetcher is used to fetch metadata from ECHO metadata
server; the metadata transformer is responsible for transform metadata from one form to another; the metadata register is
in charge of registering ISO19139-based metadata to CSW. A prototype system is designed and implemented by using the service
middleware technology and a standard interface and protocol. The feasibility and the response time of registry and retrieval
of MODIS data are evaluated by means of a realistic LPDAAC_ECS MODIS data center. The implementation of this prototype system
and the experiment show that the architecture and method is feasible and effective. 相似文献
20.
基于元数据管理的环境地理信息系统充分运用元数据管理理论进行系统开发,建立开放式的系统架构,形成了环境地理信息系统综合运用平台框架.该系统把元数据作为系统的核心数据内容,其最重要的技术特点是通过对元数据的自定义来实现数据的扩展性. 相似文献