A closer look at Earth, from space UM satellite's data will be 10 times more accurate

March 20, 1997|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

The University of Maryland College Park has landed a $60 million NASA contract -- believed to be the largest in the history of the university system -- to build and fly a satellite to improve man's understanding of Earth's forests, climate and weather.

Called the Vegetation Canopy Lidar (VCL), the spacecraft will use remote-sensing lasers to gather fundamental data on Earth's vegetation and topography 10 times more accurate than anything now available.

Other scientists will use the new databases to develop a better understanding of how forests, landforms and the atmosphere interact to produce weather and climate changes.

Dr. Ralph O. Dubayah, 38, a professor of geography specializing in remote sensing and high-speed data processing, will oversee the construction and launch of the environmental satellite.

He predicted it would produce a "revolutionary" storehouse of information that will prove "highly unique and highly catalytic in helping us understand a whole range of Earth problems," from deforestation to climate change.

It is expected to help in the development of better computer programs for forecasting the weather.

University spokesman Roland King called the grant "absolutely immense."

"This is of major importance to the university and certainly underlines our strength in the sciences," he said.

Once the spacecraft is launched, the two-year mission will be controlled from a computer center on the College Park campus. And all data processing will be done at the University of Maryland Institute for Advanced Computer Studies.

But not all of the money will be spent at College Park.

Dubayah said the VCL spacecraft will be built by CTA Space Systems of McLean, Va. Its scientific instruments will be built at the Goddard Space Flight Center in Greenbelt, but its lasers will be manufactured by Fibertek Inc. of Herndon, Va.

Day-to-day project management will be handled by Omitron Inc. of Greenbelt.

Dubayah and his team have just three years -- until spring of 2000 -- to build and orbit their 660-pound spacecraft. It will be launched aboard a Pegasus rocket fired from beneath the wing of a converted airliner.

Dubayah said the mission was made feasible by the recent development of vital computer programs and lasers reliable enough to fire 290 times per second over land and still survive a two-year mission.

From its orbit 248 miles above Earth, VCL will eventually pass over 98 percent of the world's forest.

It will fire its five near-infrared lasers at the ground, and the reflected signals will yield data on the height and thickness of the forest canopy, its mass and the topography of the land beneath it.

"It's good for a variety of things," Dubayah said. "Most importantly, the height of the trees is highly correlated with their biomass. It will enable us for the first time to have a fairly accurate estimate of global vegetation biomass."

Knowing the mass of the world's vegetation will help scientists more accurately estimate how much carbon it contains. That is an important missing piece in many attempts to figure out how Earth's climate may change as a result of human society's combustion of fossil fuels.

Combined with data from more traditional studies, the vegetation information can aid studies of the biodiversity of animal life and deforestation. VCL's topographic data may also help produce "unparalleled" information about the planet's landforms, Dubayah said.

Knowing how much of Earth's surface is covered by various types of vegetation is also crucial for creating computer models capable of predicting global climate change.

Pub Date: 3/20/97

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