Satellites to the Rescue
By Darby Patterson
Government Technology Magazine
Geographic Information Systems (GIS) have become increasingly valuable in the electronic age. This very sophisticated technology is used by governments in countless ways – in fact, experts estimate that GIS permeates at least 80 percent of government’s activities.
Obvious uses include maps for city planners, demographics about population, environmental information and transportation. In New York City, where a highly effective GIS program called NYCMap (pronounced “nice-map”) has been underway for several years, the system suddenly became a critical disaster assessment and recovery tool when Manhattan became a terrorist target. With the subway system in chaos, roads badly congested or closed and tunnels destroyed, transportation became an immediate challenge. The electronic maps helped to direct emergency crews to hot spots, calculated which traffic routes were useable and helped to monitor Ground Zero conditions.
To respond to the emergency demands, maps from several sources were integrated into a single map – overlaid to reveal specific information. By viewing the maps, emergency responders were able to make informed decisions about how to proceed with recovery efforts. At the same time, new maps were being created. According to Avi Duvdevani, acting chief information officer for the city, photographers were taken aloft to shoot specific areas over Ground Zero. The pictures of the rubble and damaged buildings were then overlaid on existing maps of infrastructure such as sewer and gas lines.
Images on NYCMap are particularly accurate because they employ a system that creates an “orthophotographic view” that makes a digitized, seamless map. It also shows the planes and outlines on the ground, such as individual parking spaces. The GIS mapping method is one of the most accurate available, with only one to two-foot disparities between the aerial photo and reality.
The project was started by the city’s Department of Environment to create a map that showed water and sewer infrastructures, in relation to physical features on the ground. The first maps were created with approximately 7,5000 aerial photos in a project that took about three years to complete. Other departments quickly grasped how useful such maps could be in daily business and added data to the system. One of the more creative applications was for “rat control,” a task that falls under the jurisdiction of the city’s Office of Emergency Management (OEM).
The department was able to pinpoint what regions of the city were registering the most complaints about rat infestation. Eradication of the pests that pose health treats, became a duty shared by several agencies that used the GIS data to create efficient and targeted programs.
This past summer, GIS was used to address yet another health concern – outbreak of the West Nile Virus. Health care professionals and the public were able to access information about places the virus might exist – such as areas of standing water where mosquitoes could breed – or where an infected animal had been found.
The photos produced by NYCMap are so detailed that it’s possible to see home plate in Yankee Stadium, individual fire hydrants and crosswalks on city streets. With this kind of clarity and accuracy, it is not surprising that the system became a foundation in the recovery efforts at the World Trade center.
A similar technology, Global Position Systems (GPS) was used to monitor movement of damaged building on the ground. Using highly sensitive surveying equipment, a beam of light was shot from a GPS device at a target affixed to an unstable structure. The slightest shift of the building caused a warning alarm to sound and signaled the evacuation of rescue workers and crews.
Sophisticated electronic systems such as GIS and GPS that have become staples in the management of government’s everyday business demonstrated their value in times of extreme emergency. Now, as the nation moves forward with a focus on national security, GIS will again show its versatility as it becomes a weapon in the arsenal of Homeland defense.
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