NASA laser probe to map Earth's forests in 3D

NASA is developing a laser-based probe for the International Space Station that will study the Earth's forests in 3D, helping to fill in missing information about their role in the carbon cycle.
Called the Global Ecosystem Dynamics Investigation (GEDI) lidar, the instrument will be the first to systematically probe the depths of the forests from space.
The system is one of two instrument proposals recently selected for NASA's Earth Venture Instrument programme and is being led by the University of Maryland, College Park.
"GEDI lidar will have a tremendous impact on our ability to monitor forest degradation, adding to the critical data needed to mitigate the effects of climate change," said University of Maryland Vice President and Chief Research Officer Patrick O'Shea.

"GEDI will be a tremendous new resource for studying Earth's vegetation," said Piers Sellers, deputy director of Goddard's Sciences and Exploration Directorate.
"In particular, the GEDI data will provide us with global-scale insights into how much carbon is being stored in the forest biomass," said.

By revealing the 3-D architecture of forests in unprecedented detail, GEDI will provide crucial information about the impact that trees have on the amount of carbon in the atmosphere.
Although it is well-established that trees absorb carbon and store it long-term, scientists have not quantified exactly how much carbon forests contain.
As a result, it's not possible to determine how much carbon would be released if a forest were destroyed, nor how well emissions could be countered by planting new trees.

"One of the most poorly quantified components of the carbon cycle is the net balance between forest disturbance and regrowth," said Ralph Dubayah, the GEDI principal investigator at the University of Maryland.
"GEDI will help scientists fill in this missing piece by revealing the vertical structure of the forest, which is information we really can't get with sufficient accuracy any other way," said Dubayah.
GEDI can do this because it's a laser-based system, called a lidar, that can measure the distance from the space-based instrument to Earth's surface with enough accuracy to detect subtle variations, including the tops of trees, the ground, and the vertical distribution of aboveground biomass in forests.

"Lidar has the unique ability to peer into the tree canopy to precisely measure the height and internal structure of the forest at the fine scale required to accurately estimate their carbon content," said Bryan Blair, the deputy principal investigator for GEDI at Goddard.