From an orbit 450km above Earth, a new satellite produces images clear enough to distinguish an SUV from a pickup, the lines on a tennis court and the shadows of a foursome on a golf course.
Mapmakers, archaeologists and cities struggling with urban sprawl are eager to obtain the super-sharp pictures from Quickbird, which recently began snapping the most detailed satellite images ever available to the public.
"We're one of the very first people in line," said Jerry Holden, a remote-sensing manager at the conservation group Ducks Unlimited, which hopes to use Quickbird images to monitor wetlands. "There are things like vegetation studies where you need the best resolution you can get."
Quickbird's cameras can pick up objects as small as half a meter. The next-best satellite available to the public, the Ikonos satellite launched in 1999 by Denver-based Space Imaging Inc, has a resolution of closer to 1m.
Other nations, notably Israel and Russia, have high-powered satellites, too, but none as sharp as Ikonos or Quickbird. US military satellites do produce sharper images, but those are off-limits to the public.
Quickbird was launched in October by Longmont-based DigitalGlobe after a predecessor failed to reach orbit a year earlier.
It began producing images in February and selling them through resellers in March. Direct sales to the public will begin by midyear.
Early images can distinguish the lanes of a swimming pool, school buses around the Washington monument, seams in the tarmac at Washington's Reagan National Airport and a traffic jam outside the Coliseum in Rome.
More importantly, experts say, the satellite can pick up details of coral reefs, environmental damage and the slow creep of urban growth.
"There are so many cities worldwide that do not have good maps at all," said Farouk El-Baz, the director of the Center for Remote Sensing at Boston University. "Things develop so drastically that the government cannot even follow the changes or even know about them."
Ted Scambos of the National Snow and Ice Data Center at the University of Colorado in Boulder hopes to use Quickbird to distinguish how crevasses in the Antarctic ice shelf fluctuate over time.
"There are some sort of collapse pits that you could actually see," Scambos said. "There are several areas where it might be useful."
Quickbird's imaging mechanism works much like a photocopier, sweeping its lens across the terrain below.
The images are about 16km by 16km in size and can cost anywhere from US$30 to more than US$185 per 1km2 for high-quality pictures. Several can be stitched together to form much larger mosaics of terrain.
Ikonos imagery is cheaper, at about US$18 for the lowest-priced picture. And Space Imaging has an archive of about 500,000 images that sell for US$7 per 1km2, though images are not as sharp.
The camera technology in Quickbird and Ikonos is almost identical.
But because DigitalGlobe was able to get a government license to produce the clearer images, it launched Quickbird into a lower orbit than Ikonos to pick up better detail.
Space Imaging now has a high-resolution license as well, and it plans to up the ante in 2005 with a satellite whose resolution will be about 45cm, slightly better than Quickbird's. DigitalGlobe has said it plans another satellite capable of taking sharper pictures as well.



