And like all maps, these reflect the quality of underlying information. Information from sensors can give early warning of environmental hazards. Kass Green, the president of Pacific Meridian Resources, a mapping firm, expects that new images will help minimize the damage done by wildfires like those that sweep through urban areas such as Los Angeles and Oakland, California. Planning firebreaks and other preventive measures depends on accurately predicting a fire's path. When, for example, environmental groups and the Bush Administration clashed over how much old-growth forest in the Pacific Northwest should be protected as habitat for the spotted owl, competing layered maps produced by the Wilderness Society and the federal Forest Service provided a basis for negotiation, by clarifying different ways of defining old growth.
Satellite images can make things harder to hide.
The Environmental Protection Agency has used such images to help identify hazardous-waste sites and sources of water pollution. When farm boundaries are layered over images of the countryside, infrared color codes reveal whether a field is growing barley, wheat, corn, or something else. O F course, newly explicit images can also be used to make mischief. Foreign intelligence agencies are expected to be among the largest buyers of high-resolution images. Iraq would be interested in information about Saudi Arabia.