The gathering of data from above via low and high altitude aircraft or via space shuttle, sometimes known as remote sensing, has played an important part in GIS systems over the years. Though it is expensive, the large area that is covered results in lower cost per ground unit covered than can be obtained by the use of ground crews. Employing infrared technology in aerial imagery has allowed environmental studies that can reveal damaged vegetation before it is noticeable to ground-based observers, and to monitor industrial effluence. Additionally, radar and microwave techniques allow mapping tropical regions that are covered by dense clouds.

Much more recently, however, aerial imagery has made its impact on the business world. A short list of uses of aerial imagery in business might include the following:

• Infrastructure planning
• Site evaluation
• Construction progress photography
• Accident reconstruction
• Demographic analysis
• Population estimates by counting homes
• Urban street database development
• Road development
• Subtle changes in farm soil over large areas
• Environmental assessment
• Boundary settlements
• Planing and zoning data
• Commercial real estate acreage
• Landuse
• Advertising and marketing photography

The example below shows how aerial imagery can be used to provide an interactive, web-based, NIU site map for prospective students and visitors to the NIU DeKalb campus. All aerial photography on this web page was taken on February 21, 2000 by NIU graduate students in the M.S. program in Management Information Systems (MIS)--Dick Green (pilot) and Chris Schaerli and Rahul Patel (photographers). A Java applet was then constructed that allows the browser user to learn the locations of some major buildings on the DeKalb NIU campus.