Starting with this chapter, the discussion focuses will shift from previous fundamental concepts and technologies of Internet GIS to the actual application of Internet GIS in different areas, such as data sharing and data warehousing, transportation, planning, resource management, etc. This chapter will focus on applying Internet GIS in data sharing and data warehousing from both aspects of data provider and data user. Starting from the basic elements of sharing, discovering and accessing geospatial data on the Internet, it discusses metadata and two major geospatial data portals: the Geospatial Data Clearinghouse Activity at the U.S. Federal Geographic Data Committee, and the Geography Network and G.Net managed by ESRI, Inc. Examples of major geospatial data providers are also provided in the chapter.


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Chapter 11 Distributed GIS in Data Warehousing and Data Sharing

11.1. Introduction
11.2 Accessing Geospatial data over the Internet: Browsing or Searching

      11.2.1 Index and Catalog Geospatial Information

      11.2.2 Metadata Catalog Services

      11.2.3 An Efficient Search Mechanism

      11.2.4 Geospatial Data Transfer and Distributions

      11.2.5 A Data Discovery Client

11.3 National and Global Spatial Data Infrastructure

      11.3.1 The Geospatial Data Clearinghouse Activity

      11.3.2 The Framework of the Geospatial Data Clearinghouse Activity

11.4 The Geography Network and G.NET
11.5 Samples of Other Geospatial Data Providers

      11.5.1 The U.S. National Imagery and Mapping Agency (NIMA)

      11.5.2 The NASA's Terra Sensors Data Services

      11.5.3 Data Services at NASA's Distributed Active Archive Centers (DAACS)

      11.5.4 The USGS Earth Resource Observation Systems Data Centers

      11.5.5 The Terra Server

      11.5.6 Space Imaging

      11.5.7 The US Bureau of Transportation Statistics (BTS)

      11.5.8 American Factfinder - US Census Bureau

      11.5.9 The US Department of Housing and Urban Development (HUD)

11.6 Conclusions and Summary

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  • FGDC Clearinghouse (
    The Clearinghouse Activity, sponsored by the FGDC, is a decentralized system of servers located on the Internet which provide standardized metadata to facilitate query and consistent presentation across multiple participating sites. It uses readily available Web technology for the client side and uses the ANSI standard Z39.50 for the query, search, and presentation of search results to the Web client. If you are new to the idea of metadata or clearinghouse, please refer the questions and answers for an overview of the technology. If you would like to set up your own node of the clearinghouse, you may refer to the tutorial. This website also provides complete reference material for technical support and development of the Metadata. You can also search geospatial data via the clearinghouse.

  • Isite ( )
    This website is hosted by the CNIDR (Center for Networked Information Discovery and Retrieval). CNIDR provides a series infomation retrieval services to the public community, among that is the Isite. Isite is an integrated Internet publishing software package which includes a text index/search system (Isearch) and Z39.50 communication tools to access databases. Within this page, you can download the Isite software package, review the overall architecture of the package, and read the documentation. You may also find the other sites that apply the software package as well.

  • Z39.50 (
    "Z39.50" refers to the International Standard, ISO 23950: "Information Retrieval (Z39.50): Application Service Definition and Protocol Specification", and to ANSI/NISO Z39.50. The standard specifies a client/server-based protocol for searching and retrieving information from remote databases. This page, hosted by the Library of Congress, provides links to information about Z39.50 resources and about the development and maintenance of Z39.50 (existing as well as future versions) and the implementation and use of the Z39.50 protocol.

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