Original URL: http://www.theregister.co.uk/2009/06/30/nasa_japan_release_99_complete_topographic_map/

NASA, Japan (nearly) finish topographic map of Earth

Everything but the boring polar bits

By Austin Modine

Posted in Media, 30th June 2009 18:53 GMT

NASA and the Japanese government have released what they claim is the most complete topographic map of the planet yet. The data uses detailed measurements from NASA's Terra spacecraft covering 99% of the Earth's landmass, with only the boring polar bits left out.

The new elevation model of Earth was created from nearly 1.3 million individual stereo-pair images snapped by the Japanese Advanced Spaceborne Thermal Emissions and Reflection Radiometer (ASTER) aboard Terra. Each elevation measurement point is 30 meters (98 feet) apart, NASA said. The data was then given simulated natural color and draped over terrain models to strike a pretty picture:

Colorized to show elevation, image credit: NASA

Himalayan glaciers in Bhutan, image credit: NASA

Terra's newfangled map is expected to be valuable for Earth sciences, engineering, energy exploration, public works design, firefighting, recreation, city planning, and just plain folks who like pretending they can smite mortals from above. The data is being offered online at no cost.

"This is the most complete, consistent global digital elevation data yet made available to the world," said Woody Turner, Aster program scientists at NASA HQ in Washington DC. "This unique global data set will serve users and researchers from a wide array of disciplines that need elevation and terrain information."

NASA said its new data breaks the agency's own record for publishing the most complete topographic set publicly available. Previously, it was from NASA's Shuttle Radar Topography Mission, which mapped 80 per cent of Earth's landmass, between 60 degrees north latitude and 57 degrees south. The new Aster data covers from 83 degrees north latitude and 83 degrees south. (The poles are apparently of little consequence unless you're a narwhal).

"The Aster data fill in many of the voids in the shuttle mission's data, such as in very steep terrains and in some deserts," said Michael Kobrick, Shuttle Radar Topography Mission scientist at NASA's Jet Propulsion Laboratory. "NASA is working to combine the Aster data with that of the Shuttle Radar Topography Mission and other sources to produce an even better global topographic map."

What the Los Angeles Basin may look like underneath the smog, image credit: NASA

ASTER acquires its images from 15 different bands of the electromagnetic spectrum, from visible to thermal infrared light. NASA and Japan's Ministry of Economy, Trade and Industry developed the data set. A joint science team from the US and Japan validate and calibrate the instruments and data.

Some choice images are available here, complete with a video clip flyover of California and Los Angeles. The data itself is at yonder URL - although as of publication it appears to be experiencing a crippling amount of traffic. ®