|
High-resolution satellite images of Alaska now available on CD Russian black and white satellite images cover about half of Alaska and depict ground details as small as two meters Alan Bailey PNA Contributing Writer
Modern satellite technology has made it possible to photograph large areas of the earth’s surface in stunning detail. Satellite images, with ground resolutions as fine as one meter, can provide a wealth of useful information when exploring or developing remote regions such as Alaska, Mike Laserson, president of Central Trading Systems Inc. told PNA in a recent interview.
Russian images In an interesting twist of history, Russia has become a prime source of these high-resolution images. Years ago, the Soviet government used satellite imagery as part of its military program. Nowadays, Russia operates its satellite imagery program as a commercial business.
Central Trading, based in Huntington, N.Y., markets the Russian images in the United States. The company supplies the images on CD ROM, which can be viewed on a computer.
“The imaging we sell is entirely from Russia,” Laserson said. “Unlike anyone else, we do have archive imagery over Alaska.”
Increasing resolution When Central Trading went into business in 1990, it sold only the five-meter resolution images, most of which went to energy exploration geologists. Other potential applications required finer resolution, which was not available at that time.
The resolution of the images has advanced steadily during the past decade, to a point where they now reveal the kind of surface detail required for development and construction projects, Laserson said.
“Over time the products have gradually improved,” he said. “We started selling two meter data in 1993 and about a year and a half ago we started selling one meter data.”
3-D pictures of Alaska Laserson said Alaska presents some difficult challenges for satellite photography. The snow cover during many months of the year limits the time available to shoot usable pictures.
The state’s location relative to satellite orbits causes further time restrictions, Laserson said.
The Russian imagery, all of which was shot in the 1990s, includes two-meter resolution pictures of about half of the state. The images are black and white.
Although individual images display a flat picture of what is on the ground, overlapping, adjacent images snapped from slightly different angles by the satellite make it possible to view the terrain in three-dimensional relief. These so-called stereoscopic pictures allow the elevation of the terrain to be calculated for plotting on maps.
Laserson said that stereoscopic imagery at a 10-meter resolution exists for about two-thirds of Alaska.
And with the introduction of color imagery planned for 2003, Central Trading’s satellite photography program continues to develop.
With uses ranging from mapping and environmental studies to development planning, high-resolution satellite images provides a cost-effective alternative to conventional maps and aerial photographs, Laserson said.
| 