Appendix D Example Prototypes
Detailed in this section is a sample of World Wide Web sites chosen to illustrate existing elements of the distributed geolibrary vision. Each is largely isolated from one another and falls short of the full vision. Taken together, the set illustrates both what is already possible and how far we still are from a distributed geolibrary.
Microsoft's Terraserver (www.terraserver.com)
Terraserver offers digital imagery (Figure D.1) from the Russian SPIN-2 satellites and digital orthorectified photographs (orthophotos) from the U.S. Geological Survey. The archive contains over 1 terabyte of information and can be queried by pointing, zooming, and panning on a basemap or by specifying place-names. No services are provided for finding or integrating other data based on place.
Figure D.1.
U.S. coverage in the terraserver database in October 1998.
MapQuest (www.mapquest.com)
The MapQuest site offers a range of services based on its database (see Figure D.2). The map illustrates the ability to provide services based on specific collections, in addition to serving unmodified information.
Figure D.2.
Result of a request to the MapQuest site for a map centered on an address in St. Louis, Missouri.
Environmental Protection Agency ZIP Code Search (www.epa.gov/enviro/zipcodejs.html)
The U.S. Environmental Protection Agency's (EPA) web site offers several forms of place-based search through the agency's archives, including Maps On Demand and ZIP code search. From the web site:
The EPA Envirofacts Warehouse is a database that includes information on Superfund sites, drinking water, air pollution, toxic releases, hazardous waste, and water discharge permits. Through Envirofacts, you can get lists of which facilities in your neighborhood are releasing pollutants or are legally handling hazardous materials, where any Superfund sites are located and what their cleanup status is, and more. In many cases, you can link to more information about the chemicals involved at the listed sites, and find out whether they are potentially harmful.
Through Envirofacts' EnviroMapper feature, you can customize a computer-generated map of your neighborhood to view the location of EPA regulated sites, schools, churches, streams, streets, and other geographic features.
U.S. Bureau of the Census TIGER Map Server (tiger.census.gov)
The Bureau of the Census web site supports place-based search for census data. In Figure D.3 the TIGER Map Server has generated a map of part of Goleta, California, showing features selected by the user. The main purpose of the TIGER Map Service project is to provide a good-quality, national scale, street-level map to users of the World Wide Web. This service is freely accessible to the public, and based on an open architecture that allows other Web developers and publishers to use public domain maps generated by this service in their own applications and documents. We planned to provide high-quality street maps, with simple GIS capabilities such as point display and statistical choropleth mapping.
Figure D.3.
The U.S. Bureau of the Census TIGER Map Server will create maps to user specifications, based on place-based search.
U.S. Geological Survey National Atlas (www.usgs.gov/atlas)
The National Atlas web site creates and delivers maps on demand from the National Atlas database. Figure D.4 shows the initial stage of specification.
Figure D.4.
The U.S. Geological Survey's National Atlas web site, which allows users to specify and create customized maps from the National Atlas database.
MIT's Digital Orthophoto Server (ortho.mit.edu)
This Massachusetts Institute of Technology web site serves digital orthophotos (DOQs) for the area around Boston. Figure D.5 shows the index page; by clicking on a tile it is possible to retrieve the associated data at a user-defined level of resolution.
FIGURE D.5.
Index page for MIT's Digital Orthophoto server, which provides downloadable orthophotography for the Boston area.
Alexandria Digital Library (alexandria.ucsb.edu)
The Alexandria Digital Library (ADL) is the product of a research project at the University of California, Santa Barbara, funded through the Digital Library Initiative of the National Science Foundation, the National Aeronautics and Space Administration, and the Defense Advanced Research Projects Agency. Figure D.6 shows the first screen in ADL's process of defining a place-based search. Additional properties can be specified to narrow the search, which is then applied to the order 106 data sets in the current ADL collection.
Figure D.6.
Opening screen of the Alexandria Digital Library's Java-based engine for searching its collection based on location.
Microsoft's HomeAdvisor (www.homeadvisor.com)
This Microsoft web site is designed to help people searching for homes. It includes the ability to access demographic and other information about neighborhoods (see Chapter 1), search listings, and estimate payments. Figure D.7 shows the opening screen.
Figure D.7.
Microsoft's HomeAdvisor web site.
