The CNSDTF topological vector model and structure

Geo-Spatial Data Transfer Standard is an important part of “National Spatial Data Infrastructure (NSDI)”, as well as a necessary means for data sharing. “Chinese National Geo-Spatial Data Transfer Format (CNSDTF)” was approved by National Quality Technology Supervise Bureau in 1999 with the standard serial number of 17798-1999. It is designed to support vector and raster spatial data. This paper describes the vector part of CNSDTF, including design ideas, main characters, conceptual model, definition of spatial object, and file structure.     

中国矢量数据交换格式的应用研究

在研究中国《地球空间数据交换格式》标准的矢量数据交换格式的基础上 ,提出了矢量空间数据的两种属性分类概念 ,并就标准的功能扩充作了简要的论述和建议     

电子地图的数据交换(CNSDTF)实现

电子地图是传统地图的矢量数据格式，由于采用不同的软件平台和不同的数据格式，因此在进行数据交换和数据共享时经常需要进行数据格式的转换。中国《地球空间数据交换格式》标准中给出了矢量数据交换的标准格式，对于GIS应用中的矢量数据交换基本已满足要求，但对于电子地图的交换尚有不足。本文在认真研究了电子地图的一般特征后，提出了电子地图所具备的图形表现属性不同于非图形属性的概念，在不违背标准的基本原则下扩充了现有标准的格式，大大方便了电子地图数据的交换，并且给出了程序实现的简要流程。     

ESRI地理空间数据与AutoCAD数据的交互共享

近年来,GIS发展迅猛,并呈向其他相关行业渗透、延伸趋势。地理空间数据的跨行业交互共享成为一种新的行业需求。以应用广泛的AutoCAD、Shape数据为例,对2种数据的差异和联系进行了详细分析,深入探讨了二者交互共享的必要性和可能性,归纳总结了实现其共享的方式和建议。力求探索一条基于ESRI空间数据和AutoCAD数据...     

The SDTS Topological Vector Profile

Because the Spatial Data Transfer Standard (SDTS), also Federal Information Processing Standard 173, is designed to support any type of spatial data, implementing all of its options at one time is impossible. Instead, the SDTS is implemented through the use of profiles, which are limited subsets of the SDTS. The first profile developed is the Topological Vector Profile. This profile supports geographic vector data with geometry and topology. It does not support raster data, graphic representation modules, and geometry-only vector data. This profile was tested in 1992 in order to validate it. It will be submitted to the National Institute of Standards and Technology as an amendment to the SDTS.     

基于CNSDTF的国家基础地理数据共享研究

针对多比例尺国家基础地理矢量数据的特点,分析了最新发布的《地理空间数据交换格式》国家标准应用于国家基础地理信息共享的可行性。结合国家、省、市基础地理数据交换的需求,设计和开发了地理信息数据格式转换软件(GIFT),并在国家基础地理信息中心进行了测试与验证。     

基于元数据面向电子政务的空间信息共享

近几年随着我国电子政务系统的不断建设,资源共享已经成为一个十分迫切的问题。本文探讨电子政务建设中的空间信息共享问题。结合当前电子政务建设中空间信息的应用现状,提出在电子政务建设中数据共享特别是空间信息共享的解决方法,及基于电子政务中的空间元数据标准和数据共享安全机制,采用分布式结构实现政府各部门之间的针对电子政务应用的空间信息共享。     

Multidimensional and quantitative interlinking approach for Linked Geospatial Data

ABSTRACT

Linked Data is known as one of the best solutions for multisource and heterogeneous web data integration and discovery in this era of Big Data. However, data interlinking, which is the most valuable contribution of Linked Data, remains incomplete and inaccurate. This study proposes a multidimensional and quantitative interlinking approach for Linked Data in the geospatial domain. According to the characteristics and roles of geospatial data in data discovery, eight elementary data characteristics are adopted as data interlinking types. These elementary characteristics are further combined to form compound and overall data interlinking types. Each data interlinking type possesses one specific predicate to indicate the actual relationship of Linked Data and uses data similarity to represent the correlation degree quantitatively. Therefore, geospatial data interlinking can be expressed by a directed edge associated with a relation predicate and a similarity value. The approach transforms existing simple and qualitative geospatial data interlinking into complete and quantitative interlinking and promotes the establishment of high-quality and trusted Linked Geospatial Data. The approach is applied to build data intra-links in the Chinese National Earth System Scientific Data Sharing Network (NSTI-GEO) and data -links in NSTI-GEO with the Chinese Meteorological Data Network and National Population and Health Scientific Data Sharing Platform.     

基于簇模型的矢量地图数据的高效压缩方法(英文)

This paper proposes a new method for the compression of vector data map. Three key steps are encompassed in the proposed method, namely, the simplification of vector data map via the elimination of vertices, the compression of removed vertices based on a clustering model, and the decoding of the compressed vector data map. The proposed compression method was implemented and applied to compress vector data map to investigate its performance in terms of the compression ratio and distortions of geometric shapes. The results show that the proposed method provides a feasible and efficient solution for the compression of vector data map and is able to achieve a promising ratio of compression and maintain the main shape characteristics of the spatial objects within the compressed vector data map. Supported by the National 863 Program of China (No. 2007AAl2Z241), the Program for New Century Excellent Talents in University (No. NCET-07-0643), the National Natural Science Foundation of China (No. 40571134, No. 40871185), the National 973 Program of China (No. 108085).     

地理空间数据共享机制研究

地理空间数据是地理信息系统的重要组成部分，是国家空间数据基础设施建设的主体，但地理空间数据的多样性导致了数据共享的困难。文中探讨了产生地理空间数据多样性的原因，分析总结了现有的地理空间数据共享的解决方案，并对地理空间数据共享的发展方向进行了展望。     

Developing a Raster Profile for the Spatial Data Transfer Standard

The Spatial Data Transfer Standard (SDTS) was designed to transfer both vector and raster data sets. In the early development of the SDTS, the designers recognized that there was a need to transfer raster data in addition to the more challenging vector data. As a result, the SDTS includes a “raster module” that accommodates a variety of raster data structures and formats. A raster profile is being developed that will exercise a selected subset of SDTS capabilities in order to provide a simple-to-use transfer of complete raster data sets.     

Profile Development for the Spatial Data Transfer Standard

The Spatial Data Transfer Standard (SDTS), or Federal Information Processing Standard (FIPS) 173, is designed to support all types of spatial data. Implementing all of the standard's options at one time is impractical. Therefore, implementation of the SDTS is being accomplished through the use of profiles. Profiles are clearly defined, limited subsets of the SDTS created for use with a specific type or model of data and designed with as few options as possible. When a profile is proposed, specific choices are made for encoding possibilities that were not addressed, left optional, or left with numerous choices within the SDTS. Profile development is coordinated by the U.S. Geological SUIVey's SDTS Task Force. When completed, profiles are submitted to the National Institute of Standards and Technology (NIST) for approval as official amendments to the SDTS. The first profile, the Topological Vector Profile (TVP), has been completed. A Raster Profile has been tested and is being finalized for submission to the NIST. Other vector profiles, such as those for network and nontopological data, are also being considered as future implementation options for the SDTS.     

．NET环境下多尺度地理空间数据组织方法研究

在.NET环境下运用面向对象技术对地理空间数据进行合理组织,根据地物分类编码和制图综合知识对数据进行显示等级界定,从而在一定程度上解决地理窄间数据多尺度表达的问题;将空间数据和属性数据同时存储,解决了数据在一致性维护、并发控制以及海量空间数据存储管理上的缺陷;根据图幅和分层来建立R树索引,提高了索引的速度.     

地学栅格格网数据质量评价指标与方法

栅格格网数据在GIS空间分析中具有巨大优势,但是其质量优劣很大程度上影响着这些基础数据的应用能力。本文结合地球系统科学数据共享网(科学数据共享工程试点)中栅格格网数据现状,提出该数据质量评价的指标和方法。具体指标包括图形、属性、时间和元数据四个大的要素集,通过与精度、逻辑一致性与完整性的匹配,组成一个的评价指标矩阵。基于缺陷扣分法和加权平均法设计了数据质量评价技术路线,并以地球系统科学数据共享试点中的栅格格网数据为实例,验证了本技术方法。     

基于空间方向相似性的面状矢量空间数据匹配算法

数据一致性匹配处理技术是空间数据融合中的关键技术。采用方向关系矩阵模型进行空间方向关系描述,讨论了一般情况下的空间方向相似性计算,提出了基于空间方向相似性的矢量数据匹配算法流程。最后,以面状目标为研究对象,以某地局部地区居民地数据为例,对基于空间方向相似性的矢量数据匹配算法进行了试验与分析。     

服务于PDA的矢量数据分块存储数据结构的研究

数据结构、数据模型是GIS领域中一个比较重要的研究方向，目前GIS中较成熟的数据结构均是针对个人PC机或工作站硬件环境，并不适合以掌上电脑为平台的移动GIS系统。针对以掌上电脑为代表的智能移动终端，提出了一种矢量数据分块数据结构模型。该数据结构适用于以PDA智能终端为硬件平台的移动GIS系统，是实现矢量图形数据存储与快速显示的技术关键。     

基于天地图·新疆自治区节点矢量数据与国家主节点矢量数据融合技术方法探讨

主要阐述了"天地图·新疆"自治区节点矢量数据与国家主节点矢量数据融合生成技术路线、技术要求,可为天地图其他省(自治区)级节点矢量电子地图数据融合工作提供参考。     

An Implementation Strategy for SDTS Encoding

Any implementation plan for the Spatial Data Transfer Standard (NIST 1992) must include the following minimum set of tasks: conceptual, logical, and format level mappings; verification of the mappings; and systems development. These tasks are used as a guide in formulating specific project plans. For a data producer to implement an encoding capability, the tasks are learning the SDTS, conceptual mapping, module mapping, building sample modules, format mapping, encoding a sample data set, and developing the system. NOTE: This article assumes familiarity with the SDTS constructs of modules, fields, and subfields and the relationship of the SDTS to ISO 8211 (American National Standards Institute 1986).     

Opportunities for Use of the Spatial Data Transfer Standard at the State and Local Level

Dramatic changes in the way that spatial data have been collected and processed over that last 20 years is leading to a rethinking and restructuring on the most efficient ways to handle geographical information. These changes are taking place at the federal, state, and local governmental levels with great potential for the private sector as well. The formal adoption of the Spatial Data Transfer Standard (SDTS) as the federal database transfer standard for spatial databases signals a new era in this long chain of developments. It offers more flexible and efficient database transfers than earlier tools, and will become the workhorse for implementing the new National Spatial Data Infrastructure. It offers organizations a standard that will make possible and practical a much wider sharing of databases than is currently being done today. Use of the SDTS presents an opportunity to many organizations to share data more easily and reduce the duplication of expensive spatial database resources.     

构建智能交通地理信息及定位平台

计算机技术、通信技术、现代控制技术、全球定位技术和地理信息系统技术为智能交通系统 (ITS)的建设提供了可靠的技术支撑。描述地球表面的基础地理信息数据是国家空间数据基础设施建设中的重要组成部分。交通地理信息及定位平台是面向交通运输 ,以地理信息系统和空间定位技术为依托的广泛概念 ,构架交通地理信息及定位平台 ,提供车辆在四维时空中的位置和有关空间目标描述的技术和信息 ,为实现交通智能化奠定基础。