基于XML的GOMS元数据描述体系

地球信息科学元数据标准已经进入草案实施阶段,但仅仅针对有限的公共实体进行标准制定。GOMS是在地球信息科学元数据标准的基础上,综合了CIMI,根据地球科学的学科特点扩展而来,是一种适合在网上检索、交换、共享地学标本的网络信息资源描述体系。XML是W3C推出的元数据标准可扩展语言,为元数据的编码、交换和重用提供了基础框架。本文以地球科学数字博物馆中的地学标本元数据标准为研究对象,利用XML进行了描述,使得专用于地学领域的标本描述转换成通用的机器可理解的元数据,对于集成不同来源的地学标本描述,建立基于Internet的地学标本信息的管理服务体系提供了可能性。     

Semantic interoperability:a metadata mediator approach

1 IntroductionWith fast development of infonnahon technology (IT), such as network and collUnbocation teClmology, itis necesseq to sharing geographical information (GI) through network. There are a lot of GI resourcesconnected by the netWork, which giVes good chance for accessing GI, but how to get the infonnationwhich we Wanted is a Challenge. That is because data is not only a Symbol, but it also needs to indiCate themeaning which it eXPresses. Due to the shared data coining from dif…     

元数据技术在地学数据共享网络中的应用探讨

指出元数据的可扩展性和互操作性是其在地学数据共享网络中应用的关键。针对地学数据共享网络,建立了元数据的扩展模式,并依此构建多学科元数据可扩展体系;分3个方面分析了元数据互操作技术,包括元数据映射、RDF技术框架和SRW服务。     

福州市勘测档案信息化建设研究

近年来城市勘测行业信息化建设发展迅速,全站仪、掌上电脑、计算机成图、3S技术的普及应用,使得信息采集、处理、管理和应用实现了向内外业一体化作业的转变,勘测产品的保存也由过去的模拟形式向数字化形式转变,电子档案日益普及.     

气象数据文件快速下载服务系统的设计与实现

有效地为专业和业务用户提供快速批量下载气象数据服务,需要一种新型数据服务系统,以弥补现有气象数据共享服务系统的不足。该文在分析气象资料服务系统发展阶段和技术特点的基础上,根据业务需求设计了一个基于元数据技术的、针对专业和业务用户的、能快速批量下载数据的新型气象资料服务系统。该系统基于前台应用系统和后台管理系统实现了批量下载、文件目录导航、数据同步更新、多线程断点续传、安全管理和灵活配置等功能。该系统是对气象资料服务方式的一种全新设计,系统发布后得到专业用户的肯定,具有广泛的推广价值,对气象数据服务系统的技术开发有较好的参考作用。     

数字区域应用基础设施研究

针对当前数字区域工程建设普遍存在的一些问题,提出“数字区域”应用基础设施的概念,对其研究背景、参考模型和面向信息共享的公共应用服务平台进行了论述。数字区域应用基础设施是在区域网络基础设施和数据基础设施上层的基础设施,它为电子政务、电子商务、数字城市等各种数字区域信息化应用工程提供基础性的应用服务支撑,由专业信息服务机构、管理办法、标准规范、关键技术和公共应用服务平台构成。信息服务机构是数字区域应用基础设施的主体,是有效联系信息需求方和信息拥有方的桥梁;公共应用服务平台是数字区域应用基础设施的核心,为区域信息共享和交换提供了统一的构架和解决方案。其中,元数据管理和目录服务平台为信息的发布和查询提供了“一站式”入口;信息共享与协作服务平台实现了分布式数据库的信息共享和交换;地理空间信息网络服务平台实现了地理空间信息的集中式共享。最后,总结了“数字福建”应用基础设施建设的成果,对“十一五”“数字福建”工程的需求和发展作了展望。     

An Overview of Surface-Based Precipitation Observations at Environment and Climate Change Canada

The objective of this paper is to provide an overview of the present status and procedures related to surface precipitation observations at Environment and Climate Change Canada (ECCC). This work was done to support the ongoing renewal of observation systems and networks at the Meteorological Service of Canada. The paper focusses on selected parameters, namely, accumulated precipitation, precipitation intensity, precipitation type, rainfall, snowfall, and radar reflectivity. Application-specific user needs and requirements are defined and captured by World Meteorological Organization (WMO) Expert Teams at the international level by Observing Systems Capability Analysis and Review (OSCAR) and WMO Integrated Global Observing System (WIGOS), and by ECCC user engagement initiatives within the Canadian context. The precipitation-related networks of ECCC are separated into those containing automatic instruments, those with human (manual) observers, and the radar network. The unique characteristics and data flow for each of these networks, the instrument and installation characteristics, processing steps, and limitations from observation to data distribution and storage are provided. A summary of precipitation instrument-dependent algorithms that are used in ECCC's Data Management System is provided. One outcome of the analysis is the identification of gaps in spatial coverage and data quality that are required to meet user needs. Increased availability of data, including from long-serving manual sites, and an increase in the availability of precipitation type and snowfall amount are identified as improvements that would benefit many users. Other recognized improvements for in situ networks include standardized network procedures, instrument performance adjustments, and improved and sustained access to data and metadata from internal and external networks. Specific to radar, a number of items are recognized that can improve quantitative precipitation estimates. Increased coverage for the radar network and improved methods for assessing and portraying radar data quality would benefit precipitation users.     

地理国情普查外业调查轨迹整理方法研究

在地理国情普查元数据内业编辑整理阶段,需要对轨迹整理的方法进行分析与比较,在Arc GIS环境中,本文探索出了一套质量好、精度高、效率高、实际操作性强的轨迹整理方法,利用追踪获取轨迹方法整理的外业调查元数据达到了验收与质量评定规定要求,在实际生产中可广泛应用。     

大型遥感图像处理系统中集成数据库设计及应用

大型遥感图像处理应用系统中，往往需要实时获取各种背景或专题数据，该过程即是数据动态集成过程。集成数据库是建立在各种专题数据基础上的数据集成使用框架体系，该文描述了集成数据库的结构及各类子库的组成，根据项目的特殊需求提出了虚拟数据库概念，并结合实例说明了集成数据库以元数据为链条的使用机制与方法。     

Earth observation metadata ontology model for spatiotemporal-spectral semantic-enhanced satellite observation discovery: a case study of soil moisture monitoring

Monitoring soil moisture with satellite sensors is an effective approach for agricultural drought assessment. Currently, large quantities of sensor-derived observation data with different observation metadata models exist, and they require efficient and accurate methods of discovery. In this study, an earth observation (EO) metadata ontology with a spatiotemporal-spectral-enhanced structure is designed to solve this problem. The ontology is based on the proposed EO metadata model, which is composed of nonfunctional and functional sub-modules and supports the Open Geospatial Consortium EO profile of observations and measurements. Using EO metadata ontology, an application for soil moisture monitoring in Hubei Province in China is tested. The results indicate that metadata retrieval with a spatiotemporal-spectral-enhanced method can efficiently achieve fine-grained discovery of qualified EO metadata and obtain soil moisture monitoring information from sensor images. In summary, the spatiotemporal-spectral semantics in the proposed ontology demonstrate the use of EO metadata in the context of a soil moisture monitoring application, improving the efficiency and accuracy of EO metadata discovery.