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Build Your Own Geography Network
The Internet has enormous potential
for publishing and distributing geographic information.
For most organizations, the greatest cost of developing
a geographic information system (GIS) is the acquisition
and maintenance of data. Though geographic data has never
been more plentiful than it is today, much of it remains
difficult to find and access in formats that can be easily
used. The Internet is helping solve this problem by offering
a platform for data sharing and discovery that is becoming
pervasive.
By leveraging the power of the Internet,
the Geography NetworkSM is providing access to
geographic information in open formats that can support
users of all types. The technology used to build the Geography
Network is now available for other organizations that would
like to build a geography network of their own. Here's how…
Geography Network
Overview
Building a Geography Network with ArcIMS
Implementation Steps
Additional Information
Geography Network
Overview
The Geography Network is a framework
for sharing and discovering GIS data and services on the
Internet. It is based on the concept of a geospatial data
clearinghouse developed by government organizations around
the world. It provides a mechanism for GIS users to publish
and access GIS data and services worldwide. The Geography
Network consists of three parts
- Web Site (www.geographynetwork.com):
The Web site serves as a clearinghouse to discover and
access geographic content registered in the Geography
Network. The site is built around a catalog of the Geography
Network content and provides tools to discover and access
this content. This catalog is powered by the ArcIMS Metadata
Server. The ArcIMS Metadata Server supports the publication
and retrieval of metadata (i.e., reference information)
about content available through the Geography Network.
- User Communities: These
are groups of organizations or individuals that use Geography
Network content to support their professional or personal
interests. User communities are often organized around
a geographic area of interest (e.g., Texas) or an industry
area of interest (e.g., natural resources). These communities
may access Geography Network content in different ways
(e.g., directly through GIS tools or indirectly through
custom Web applications).
- Content Providers: Content
providers are government and commercial organizations
that provide access to thousands of content elements including
maps, data, services, and applications. The content is
maintained in a distributed environment so that it may
typically be accessed directly from the source.
Building a
Geography Network with ArcIMS
The Geography Network framework
can be leveraged by many types of organizations, both government
and commercial, to collect and publish geographic content
for its user community. For example, a state-level government
agency may want to provide a clearinghouse for geographic
content available in its state. An international health
organization may wish to develop a clearinghouse for health-related
geographic content around the world. These clearinghouses
would each represent a geography network, comprised of organizations
that support a common user community.
One tool that may be used to support
the development of a geography network is ESRI's ArcIMS
software. ArcIMS is ESRI's solution for distributing mapping
and GIS data and services on the Web. One of the most significant
features included in ArcIMS is the ability to create a central
repository for publishing and browsing metadata over the
Internet. Metadata can be authored using ESRI's ArcGIS ArcCatalog
application, published to a metadata server, and then quickly
searched by others. Along with ArcIMS software's metadata
services, users also receive the Metadata Explorer, which
is a JavaServer Pages (JSP) application that can be used
to build a customized, browser-based means of searching
for data. Users can use ArcIMS map services to publish data
for immediate access. In these ways, ArcIMS provides an
out-of-the-box toolkit for building a geography network.
Implementation
Steps
Below is a summary of the typical steps needed to build
a geography network using ArcIMS. Documents at the bottom
of this page include additional information.
Prepare Data to Publish:
A geography network typically includes a variety of geographic
data sources that may be accessed as downloadable data or
streaming data through map services. To distribute data
through an ArcIMS map service, the first step is to prepare
the data for publishing. This may include development of
digital data from other sources, conversion of data to publishable
formats (e.g., shapefile, ArcSDE, TIF, MrSID), or the processing
of data to optimize performance.
- Configure ArcIMS System:
Data publishers need to configure an Internet mapping
system to publish content and support user requests. The
size of this system can vary significantly, depending
on the anticipated usage, but the system will always need
to include hardware, software, data, network, and staff
components. The system must be configured to support the
anticipated levels of usage, required levels of availability,
and planned types of applications.
- Author and Publish Map Services:
After the ArcIMS system is configured, the data provider
will need to author and publish map services. This step
will include defining the content of the map services
(i.e., which data layers to display and how), authoring
the services using ArcIMS Author, and testing the performance
of the services in the intended user environment.
- Assemble and Publish Metadata:
Once the map services are authored, or other content is
prepared for publishing, the next step is to assemble
and publish the metadata for the content. A geography
network may include many types of content such as static
map images, downloadable data, or geographic services.
Metadata must be assembled for each piece of content using
tools such as ArcCatalog, then published using the ArcIMS
Metadata Server.
- Customize and Deploy Web Site:
When the content and metadata have been published, the
Web site can be built to provide access to this content.
A geography network Web site will typically enable users
to search or browse for desired content, preview metadata
about the content, and access the content as appropriate.
The Web site may include custom applications to provide
specific functionality that is desirable for the content
(e.g., a browser-based mapping application to view multiple
map services).
Additional
Information
These documents offer additional
information on building a geography network.
If you have other questions, please
contact us.
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