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1.
The Spatial Data Transfer Standard (SOTS), as a standard, is somewhat of a paradox. Standards help to establish order and promote stability. As such, SDTS serves both as a standard and a catalyst for change. Beyond being the first major geographic information systems(GIS) standard, SOTS has invoked—and continues to invoke—significant changes throughout federal organizations and other' organizations that interact with them. The changes inspired by SDTS focus attention on the importance of GIS standards. This importance, in turn, is the underlying force in creating a GIS standards infrastructure. The infrastructure provides a mechanism/process for developing, approving, and coordinating GIS standards in the federal, national, and international communities.  相似文献   

2.
The Spatial Data Transfer Standard (SDTS) was approved by the Department of Commerce as Federal Information Processing Standard (FIPS) 173 on July 29, 1992. As a FIPS, the SDTS will serve as the national spatial data transfer mechanism for all federal agencies and will be available for use by state and local governments, the private sector, and research organizations. FIPS 173 will transfer digital spatial data sets between different computer systems, making data sharing practicable. This standard is of significant interest to users and producers of digital spatial data because of the potential for increased access to and sharing of spatial data, the reduction of information loss in data exchange, the elimination of the duplication of data acquisition, and the increase in the quality and integrity of spatial data. The success of FIPS 173 will depend on its acceptance by users of spatial data and by vendors of spatial information systems. Comprehensive workshops are being conducted, and the tools and procedures necessary to support FIPS 173 implementations are being developed. The U.S. Geological Survey, as the FIPS 173 maintenance authority, is committed to involving the spatial data community in various activities to promote acceptance of FIPS 173 and to providing case examples of prototype FIPS 173 implementations. Only by participating in these activities will the members of the spatial data community understand the role and impact of this standard.  相似文献   

3.
The Spatial Data Transfer Standard (SDTS), after nine years of development, was approved on July 29, 1992, as FIPS Publication 173. The SDTS consists of three distinct parts. Part 1 is concerned with logical specifications required for spatial data transfer and has three major components: a conceptual model of spatial data, data quality report specifications, and detailed logical transfer format specifications for SDTS data sets. Part 2 provides a model for the definition of real-world spatial features, attributes, and attribute values and includes a standard but working and expandable list with definitions. Part 3 specifies the byte-level format implementation of the logical specifications in SDTS Part 1 using ISO/ANSI 8211 (FIPS 123), a general data exchange standard.  相似文献   

4.
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.  相似文献   

5.
Australia and New Zealand are adopting the Spatial Data Transfer Standard (SDTS) as their transfer standard for geographic data. The standard requires a number of modifications to suit Australia/New Zealand requirements. These modifications primarily involve coordinate reference systems for each country, references to those standards applicable to each country and new spatial feature dictionaries. For other countries adopting SDTS, future revisions to the standard should emphasize a framework for required modifications. Australia/New Zealand have established a support body to ensure the smooth introduction of the standard within these countries. This commercial venture has been successful in promoting the standard, in providing training and in related consulting work. The US Geological Survey has been the maintenance authority for the standard. It is essential that this function continues to be provided through this body to guarantee a single interpretation of the standard.  相似文献   

6.
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.  相似文献   

7.
The Digital Line Graph level 3 (DLG-3) is the term for U.S. Geological Survey digital spatial data stored in vector form. Prior to the approval of the Spatial Data Transfer Standard (SDTS) as a Federal Information Processing Standard (FIPS), a system was developed to convert a DLG-3 data set to a sample SDTS transfer. The specifications of the SDTS Topological Vector Profile were used for the transfer (U.S. Geological Survey 1992). The process required expertise in cartography, geography, and computer science. Analysis revealed requirements for processes to transform spatial addresses, to translate and map DLG-3 spatial objects and attribute pairs to the SDTS, to compile data not available in computer-readable form, and to convert files to FIPS 123 (ISO 8211) standard. Mapping data to the SDTS proved to be complex and highlighted the need for appropriate training with regard to the SDTS and FIPS 123. Several issues were raised, such as the source of data quality information, platforms supported by the FIPS 123 Function Library software, and attribute translation criteria.  相似文献   

8.
Present efforts to implement the Spatial Data Transfer Standard (SDTS) within the Commonwealth of Virginia are centered in Virginia's Council on Information Management (CIM). Since 1992, mapping, surveying and land information systems activities have been identified as a responsibility of the Council "The promotion of access to federal and other digital data banks through standards" is an area of CIM interest specified in the Code of Virginia. Prior to adoption of the SDTS by Virginia in November 1994, a Technical Advisory on the SDTS was issued and a SDTS Training and Education Plan was adopted. The Council on Information Management has worked with the USGS SDTS Task Force in developing this plan.  相似文献   

9.
For more than a decade, efforts to develop and specify the U.S. Spatial Data Transfer Standard (SDTS) have on many occasions encountered limitations in both theory and "gaps in our knowledge" which have hindered its development. This work examines broad categories of these limitations from the perspective of research needs, to encourage further research on these topics. Areas in need of further study include fundamental concepts, the specification and use of spatial objects, spatial data quality, entity definitions, the data transfer mechanism, and international comparison of transfer mechanisms. In many cases recent research progress has been made in these areas and this progress is pointed out. A number of high-priority research areas are identified. It is hoped that this work will encourage more research effort to be directed towards these areas, which will benefit not only the development of spatial data transfer standards but also the spatial data sciences in general.  相似文献   

10.
A processor to support the Spatial Data Transfer Standard (NIST 1992) is being designed. The Spatial Data Transfer Processor will support both encoding and decoding operations. The system will have five components: transfer manager, content encoder, format encoder, content decoder, and format decoder. No component will have expertise in more than one area. The system design should be used as a guide when developing software for the SDTS. NOTE: Readers should be familiar with mapping concepts described in the article “An Implementation Strategy for SDTS Encoding,” located elsewhere in this issue.  相似文献   

11.
The Census Bureau is committed to using the Spatial Data Transfer Standard (SDTS) and is developing an extract from the Census TIGER? called the TIGER/SDTS?. A single file of the prototype TIGER/SDTS is now available with which interested data users may experiment. This paper will graphically describe some of the SDTS concepts and census geographic concepts used in the TIGER/SDTS. The Census TIGER? and the TIGER/SDTS? are trademarks of the Bureau of the Census.  相似文献   

12.
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.  相似文献   

13.
空间数据仓库的技术与实践   总被引:33,自引:0,他引:33  
赵霈生  杨崇俊 《遥感学报》2000,4(2):157-160
空间数据仓库(Spatial Data Warehouse)是GIS技术和数据仓库技术相结合的产物,它大大扩展了GIS的应用功能,为逐渐兴起的全球变化和区域持续发展研究以及复杂的商业地理分析提供强有力的支持。该文主要从空间数据仓库的起源、特征、体系结构、关键技术与应用等方面来探讨空间数据仓库这一全新的GIS应用。  相似文献   

14.
15.
Oracle数据库空间数据插件技术初探   总被引:3,自引:0,他引:3  
从基本概念,数据模型,应用功能等方面介绍了空间数据插件技术。  相似文献   

16.
This article investigates a new, integrated technique for storing and retrieving spatially varying data quality information in a relational spatial database. Rather than storing global data quality statements, the system enables data quality information to be referenced to a spatial framework, individual spatial objects, or even parts of spatial objects. The integrated model, called as RDBMS for Spatial Variation in Quality (RSVQ), allows flexible storage of spatially varying data quality information, and seamless querying irrespective of the underlying storage model. RSVQ is founded on a formal model of relational databases, defining a new derived, polymorphic query operator      to join quality data with spatial data. The      operator is implemented in an extension to SQL as a new WITHQUALITY keyword. A performance evaluation of RSVQ was conducted, using an Oracle Spatial database and a case study of cadastral data for parts of Victoria, Australia. The results of this evaluation demonstrated that the system is practical and efficient for a wide range of queries, as well as indicating the performance trade-offs associated with the different data quality storage models. Using the integrated RSVQ approach provides the potential for a single, consistent, database engine for a wide range of existing and proposed spatial data quality management systems.  相似文献   

17.
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).  相似文献   

18.
The explosion of computer processing capabilities for manipulating geographic data has produced a concomitant increase in the number of geographic data file formats available. The many formats make it difficult to exchange and manipulate geographic data from several sources, and sometimes even from the same source. The U.S. Bureau of the Census has been a contributor to the “Yet Another Geographic File Format” movement over the past two decades with its Address Coding Guides (following the 1970 decennial census), the GBF/DIME-Files (following the 1980 decennial census), and four different versions of its TIGER/Line files at various times during the 1990 decennial census cycle. The TIGER data base is a massive computer file that provides geographic information about the entire United States and its territories in great detail, down to the individual city block and its component boundary features. Its value to more than Census Bureau activities is enormous. To enhance the value of the TIGER data base, and to make it easier to use, the Census Bureau is releasing the file in the new Spatial Data Transfer Standard (SDTS) format. The benefits of a standard transfer format are manifold. This paper discusses some of the intergovernmental activities that were required before the exchange standard was adopted and some of the problems of implementing the standard within the Census Bureau. The Census Bureau is not alone in its decision to release geographic data files in the SDTS format, and some of the benefits of using the standard for exchanging data among agencies also are described.  相似文献   

19.
Developers of the Geographic Resources Analysis Support System (GRASS) at the U.S. Army Corps of Engineering Research Laboratories (USACERL) have been closely involved with the SDTS project since February 1992. Software for the exchange of data between GRASS and SDTS is near completion. Access to SDTS data via this software promises many benefits for GRASS users, but SDTS will also pose challenges to the GRASS user community just as it has for the creation of GRASS-SDTS software itself. Areas of difficulty include distinctions between SDTS and GRASS in the definition of certain spatial objects, SDTS metadata requirements, and accommodation within GRASS of the complex data attribute schemas that will be typical of SDTS data sets.  相似文献   

20.
The Defense Mapping Agency, the National Ocean Service, and the U.S. Geological Survey each has earned a reputation among respective user communities as a leader in producing quality data and map products that meet the highest standards. With the increased use of GIS, user communities are rapidly expanding and have now begun to overlap. With adoption of SDTS as a Federal Information Processing Standard, all federal agencies are required to use the SDTS domestically. There is additionally an emerging need to unify efforts in the development of international standards. Existing standards need to be harmonized and future standards activities need to be linked more closely. This paper reviews the roles of each agency in developing spatial data and standards for exchange and outlines leadership activities in standards development that are currently underway.  相似文献   

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