- SPECIAL REPORTS
- THE MAGAZINE
Frederick, MD (April 12, 2006) - Late afternoon on April 3, the Arkansas Geographic Information Office (AGIO) requested EarthData provide orthoimagery to support the state's response to the April 2 tornado that destroyed a reported 80 percent of Marmaduke, Arkansas. Having recently completed aerial data acquisition over the entire state for the AGIO statewide digital orthophotography program, EarthData readily agreed to produce 1-meter orthoimagery as quickly as possible to map the tornado's destruction.
"We received the imagery less than 24 hours after our request," explained Learon Dalby, AGIO GIS program manager. "The most current data we had was color-infrared photography created in 2000. The new orthos gave us several advantages: they're up to date since the imagery was just acquired this spring, and because they are "all-digital" they have much sharper contrast--clearer resolution--than our film-based imagery. As important, the new orthos were produced in natural-color, which means non-GIS users found them easier to use, a fact that is particularly important in emergency response."
Though EarthData acquired the imagery this spring, production had not begun on the Marmaduke dataset. Immediately after receiving the call from AGIO, EarthData staff isolated the appropriate raw data and started pre-processing procedures such as aerotriangulation and surface model generation. "AGIO staff built a strong partnership with EarthData from the very beginning of their 2005 mapping program," said EarthData Project Manager Raquel Charrois. "Our staff members were determined to meet AGIO needs, so we juggled priorities to deliver rectified, color-balanced 1-meter digital orthoimagery within 24 hours."
"In the early stages, the data was being used by AGIO primarily to identify obvious catastrophic loss and damage to infrastructure and property," said Dalby. "The imagery was provided immediately to the Arkansas Department of Emergency Management and is provided to federal agencies as they join our response efforts. We also anticipate that the imagery will become an integral tool in helping to distribute aid more efficiently to the residents who lost so much so quickly."