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L.A. from space: New view from JPL and NASA [Updated]

June 30, 2009 |  7:00 am

Overla

In collaboration with agencies in Japan, NASA's Jet Propulsion Laboratory has put together a topographical map that covers 99% of the Earth's land mass, a more complete map than was previously available.

"We've got everything except a very small part of the South Pole and the North Pole," said JPL's Michael Abrams, the U.S. science team leader for the Advanced Spaceborne Thermal Emission Reflection Radiometer project, also known as ASTER. "We're able to cover Alaska, Greenland, northern Asia and Antarctica."

The resolution is so clear that you can plainly see Dodger Stadium and other landmarks in pictures of Los Angeles.

The most complete previous set of topographical data, collected by the Shuttle Radar Topography Mission in 2000, included about 80% of the Earth's landmass. Because the space shuttle had a limited orbit, the radar-imaging device missed land masses above 60 degrees north and 57 degrees south in latitude.

ASTER, which started collected images in visible and infrared light nine years ago, rides aboard Terra, a satellite that is part of NASA's Earth Observing System. Its orbit enables it to collect images up to 83 degrees north and 83 degrees south in latitude and also gives it a better angle to collect data in steep mountain areas, Abrams said. The infrared instrument also collects more thermal data than previously available, he said.

The ASTER images are meant to complement the radar images, Abrams emphasized. The shuttle radar instrument has some pictures ASTER could not get because radar can penetrate clouds, which perpetually obscure some tropical areas from ASTER's sight.

Scientists recently realized they had more than 1 million scenes, enough to create a global topographic map, Abrams said. The data was released Monday, free to the public. ASTER's images have a resolution down to 50 feet, which is enough to detect houses, but not so fine as to see the shape of the house or what people are doing in the house, he said.

Scientists have already used the satellite instrument to calculate changes in the width and height of glaciers, but Abrams said he could also see a host of commercial uses for the new data. He said cellphone companies could use the new maps to scout sight lines for new transmission towers and Google could probably easily incorporate the new data into its maps.

[Updated at 8:50 a.m.: According to NASA, the cost to produce the instrument was $800,000, with the U.S. space agency contributing half.]

--Jia-Rui Chong

Photo: Los Angeles from space. Credit: Jet Propulsion Laboratory. For a high-resolution image of the Los Angeles area and other topographical images, click here

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