A Spatial Data Approach to the Social Sciences
By Kyle Bohnenstiehl, NAGIS


GIS is no longer the exclusive domain of the social scientist and academics. As information systems come online to the general public, it's necessary to focus more attention on spatial cognition. Current GIS systems require extensive training not available to the public. Ease of use is a real issue with GIS to empower new communities of users.

Given the amount of spatial data available today and the power to create complex maps and virtual worlds on a home PC, how can the Geospatial industry better serve the general populace? What is the best way to make this data available and how do we design an interface that is fast, easy to use and powerful?

"Information becomes more relevant when it's placed in a context that is meaningful to the individual, such as residents looking at crime displayed within their neighborhood boundaries, police officers viewing crimes or specific properties in their region of responsibility, or a company researching potential sites for relocation. Instead of someone else interpreting data, users perform their own query and analysis and draw their own conclusions."
Maria Macgunigal
Senior GIS Analyst,
City of Sacramento,
California
(ESRI)


Early attempts to reach large groups of people with GIS were in the form of internet mapping engines for generating driving and location maps. Users could zoom and pan around this form of spatial information but they were not necessarily creating cartographic products. These driving maps were inaccurate, in a spatial sense, for some parts of the USA, non-existent for many foreign countries and often used out-of-date or incomplete data. Concurrently, many public and private agencies had developed powerful and accurate GIS databases that while expensive to maintain, proprietary, and difficult to access, were valuable public assets. A new, more ubiquitous way of accessing, displaying, and working with georeferenced information was needed. The internet map server is a unique solution to making GIS data available over the internet. The full power of GIS can be implemented using a web browser as the interface thus making data available to everyone via the World Wide Web, independent of the operating system used. But there are still limitations to these systems, like the need for a high speed internet connection and and the resulting comparatively small viewing windows. However studies have shown that more than 70 percent of adults cannot read maps. How do we better serve the general populace as a profession? What tools do we have to work with today? What are some of the future applications we can only dream about?



Mapping via the Internet

Internet mapping is a simple and cost-effective way to implement a GIS on the Web and is an inexpensive method for reaching a vast audience. In addition, the easy-to-use browser-based format lets even novice users access maps and GIS data for analysis. There are even free map servers available at http://gislounge.com/ll/freemapservers.shtml.

The easiest systems to use, such as Terraserver , allows only viewing of satellite and aerial photos or USGS 7.5' minute topographic maps. The user enters a placename or geographic coordinate to search on and a simple viewer window displays the imagery. While not loaded with seamless global IKONOS imagery, and with some large data gaps, Terraserver does allow people to rapidly view an image of many interesting parts of the earth. There is also a service to order prints and digital images of regions like the infamous Area 51. It provides a low cost option for people who want an image of an area with little or no vector information.

A new site, Globexplorer is a similar service but only has high resolution data for selected metropolitan areas, dated DOQQ's or DRG's for much of the USA, and no data in some of the more remote reaches of the planet. Also, these servers do not allow mapping or analysis like some Internet GIS map servers.



Internet GIS map servers allow the creation of custom maps and the ability to perform spatial operations like query and buffering. These system are popular with large cities, and other government agencies. Internet mapping is simple and cost-effective to implement a GIS on the Web and to reach a vast audience. In addition, the easy-to-use browser-based format lets even novice users access maps and GIS data. The very popular National Geographic MapMachine at www.nationalgeographic.com/maps/ uses Internet mapping technology to help people better visualize and understand the world around them by giving them access to a large number and variety of data themes.



ArcIMS 3.0 by ESRI is a powerful system incorporating imagery and vector data, and the ability to edit and create new shapefiles through a web browser. MapInfo also manufacturers a similar product called MapXtreme. The drawback here and with all internet technologies is the availability of high bandwidth internet connections to end users.

The Geography Network is a global network of geographic information users and providers. It provides a central server that is needed to facilitate the sharing of geographic information between data providers, service providers, and users around the world. Through the Geography Network, users can access many types of geographic information including live maps, downloadable data, and can perform spatial analysis.



Another type of internet map server will only serve up compressed aerial and satellite imagery. These so called image servers are fairly limited in that image analysis of any type cannot be interactively performed and functions such as interactive georeferencing and 3D visualization are not currently available. Mr. Sid and ERMapper both offer their own versions of an Image Web Server. ERMapper will even let you try out a free version at their website.

An innovative type of data distribution system for GIS users is ESRI's ArcData online. If a company had data to sell or give away, this would be an appropriate model for doing so. Users can buy tiles of data organized by zip code in Shapefile format georeferenced to decimal degrees in NAD83 datum for $15 each. The data layers cover the world and contain information about demographics, transportation, socio-economic variables, natural resources and imagery. Some can be downloaded immediately for no charge and others must be ordered from the representative agency directly for a price. However, for many novice users, this would be a daunting task.

The original driving map websites have really matured in the last few years, providing accurate maps that will generally take you where you need to go (although I was once very late to dinner with an elder .com'er to whom I quipped about not needing directions). Once again no analysis can be performed but these are great ways to get maps of a region. Some sites like MapQuest will even let you download maps into your PDA for later use. Despite the wide variety of internet GIS mapping sites available, have we truly met the users needs by providing the data that people want in a format that they can easily access? This next section introduces a radical new idea to the mapping community.



.geo top level domain (TLD)

This new TLD(.org, .com, .edu, etc.), proposed by SRI, Inc., will provide a complete, virtually free, and open infrastructure for registering and discovering georeferenced information on the Internet. Georeferenced information is information that represents a geographically located place, object, or process with a geographic location. .geo could become the latitude and longitude of the Internet's virtual world. It will enable the essentially free registration and discovery of standardized geodata. Data Providers will generate and own this geodata and the georeferenced information to which it refers. They will be able to make this georeferenced information available to Internet users, either free or in return for considerations including subscriptions and major purchases of products and services.

Georeferenced information might include nearly every type of information currently available on the Internet and many types not yet available there. Similarly, many and various services will be based on this information. These services fall into three broad categories: