With all planes grounded following the Sept. 11 terrorist attacks, the only camera able to photograph the aftermath from above was one hurtling around the Earth at 17,000 miles an hour.

But that didn't stop the satellite-mounted camera, owned by Space Imaging, from snapping high-resolution, aerial images of wreckage at the World Trade Center and Pentagon that were seen by millions around the world.

Since launching the world's only commercial imaging satellite in 1999, Denver, Colorado-based Space Imaging has offered high-quality images of terrain anywhere on the globe — but few have had the import of the pictures of the terrorist attacks.

The company, which maintains an archive of satellite images on its Web site searchable by country, state, city, and even county, normally sells permission to use the images like the one above to its customers, says Gary Napier, a spokesperson with Space Imaging. This time was different.

"Something like this we didn't want to sell," he said. "We wanted to make sure everyone around the world had access to this unique view."

Judging by the increase in traffic to the site, the plan worked. In the three weeks following the attack, visitors downloaded more than one million high-resolution copies of the aerial shots. Over that same period, the site's traffic increased to 100,000 visitors per day from only 30,000 per week before the attack.

But Space Imaging didn't just provide what Napier calls "gee whiz" color photos of the aftermath. The satellite's processing system also captured "geo-rich" data normally used by government agencies and corporations to produce highly accurate maps that can detail, for example, where water can penetrate the ground or where healthy plants are in a farmer's field.

In the attack aftermath, this type of information, in which each bit (or pixel) of information is tied to a global positioning coordinate, was crucial for gauging the damage and planning the cleanup and rescue efforts. Offices such as the N.Y. governor, the Federal Emergency Management Association, the Port Authority of New York, and the Army Corps of Engineers all had access to this information, and quickly.

How the Satellite Works

Space Imaging launched its satellite, called Ikonos (Greek for "image"), in 1999. Falling around the earth at a rate of 14 revolutions per day, Ikonos orbits at a relatively low level of 423 miles above the ground, compared to 22,000 miles for satellites that provide digital television services.

What makes the satellite so powerful is its camera — custom-designed by Kodak — which allows the satellite to resolve objects down to a meter-wide scale from orbit. "It's very much like a telescope that you would use to gaze at the stars," says Napier, "except it has a very high focal-length digital processing system on it."

Geo-rich data actually comprises the lion's share of Space Imaging's sales. But recently the same satellite technology used by the government to target the back-country bivouacs and training ranges of terrorist leader Osama bin Laden has been used in other ways as well.

Two groups searching for the fate of 1930s aviatrix, Amelia Earhart, who disappeared in the Pacific Ocean while trying to become the first woman to fly around the world, have even used Space Imaging to scour remote islands for the wreckage of her plane.

Other sites, such as Terra Server and Global Security have also repackaged satellite pictures captured by the Ikonos satellite to illustrate their own content.

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