compressor stall
15th Nov 2001, 18:34
found this to be of aviation related interest.
Lasers Map Terror Wreckage
3D mapping technology helps rescue workers avoid hidden dangers in rubble of World Trade Center.
By Tech Live staff
September 25, 2001
As rescue workers in New York City sort through the giant mass of rubble that was once the World Trade Center, they are turning to 3D laser-mapping technology to get daily updates on how big, how deep, and how dangerous the wreckage is.
The mapping technique relies on lasers -- called LIDAR, for light detection and range -- and heat-sensitive cameras mounted on a plane 5,000 feet up in the air. Each second, 15,000 infrared laser pulses zap the wreckage, creating a three-dimensional map of the pile and the gaps hidden beneath it that could cause the rubble to shift -- and trap workers.
Last week, a plane flying above the still-smoking site snapped photos that revealed deep chasms at least 30 feet below street level.
"By calculating the volume of the rubble pile each day, [we] can determine whether some of those voids are collapsing and the stability of the rubble pile," said Jeff Leonard, a spokesman for EarthData International. "We can gauge what kind of danger the firefighters or emergency folks might be in."
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EarthData's twin-engine mapping plane is among the few small aircraft with permission from the Federal Aviation Administration to fly over lower Manhattan right now. Each day since September 15, the company's plane has zipped over the area, creating a detailed grid of more than 100,000 topographic elevations, each about five feet apart. The detailed maps are crucial for keeping rescue workers safe as they navigate the morass.
Other instruments aboard the EarthData plane search for thermal radiation that could indicate underground fires, which might flare up and endanger rescue workers.
EarthData also has used its airborne lasers to map areas of Times Square, discovering leaking steam before it caused a problem.
http://www.techtv.com/news/terrorism/story/0,241 95,3349534,00.html (http://www.techtv.com/news/terrorism/story/0,24195,3349534,00.html)
Lasers Map Terror Wreckage
3D mapping technology helps rescue workers avoid hidden dangers in rubble of World Trade Center.
By Tech Live staff
September 25, 2001
As rescue workers in New York City sort through the giant mass of rubble that was once the World Trade Center, they are turning to 3D laser-mapping technology to get daily updates on how big, how deep, and how dangerous the wreckage is.
The mapping technique relies on lasers -- called LIDAR, for light detection and range -- and heat-sensitive cameras mounted on a plane 5,000 feet up in the air. Each second, 15,000 infrared laser pulses zap the wreckage, creating a three-dimensional map of the pile and the gaps hidden beneath it that could cause the rubble to shift -- and trap workers.
Last week, a plane flying above the still-smoking site snapped photos that revealed deep chasms at least 30 feet below street level.
"By calculating the volume of the rubble pile each day, [we] can determine whether some of those voids are collapsing and the stability of the rubble pile," said Jeff Leonard, a spokesman for EarthData International. "We can gauge what kind of danger the firefighters or emergency folks might be in."
ADVERTISEMENT
EarthData's twin-engine mapping plane is among the few small aircraft with permission from the Federal Aviation Administration to fly over lower Manhattan right now. Each day since September 15, the company's plane has zipped over the area, creating a detailed grid of more than 100,000 topographic elevations, each about five feet apart. The detailed maps are crucial for keeping rescue workers safe as they navigate the morass.
Other instruments aboard the EarthData plane search for thermal radiation that could indicate underground fires, which might flare up and endanger rescue workers.
EarthData also has used its airborne lasers to map areas of Times Square, discovering leaking steam before it caused a problem.
http://www.techtv.com/news/terrorism/story/0,241 95,3349534,00.html (http://www.techtv.com/news/terrorism/story/0,24195,3349534,00.html)