A laser-based instrument being developed for the International Space Station will provide a unique 3-D view of Earth’s forests, 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. In particular, the GEDI data will provide us with global-scale insights into how much carbon is being stored in the forest biomass. This information will be particularly powerful when combined with the historical record of changes captured by the U.S.’s long-standing program of Earth-orbiting satellites, such as Landsat and Modis. 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. 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. Its immediate predecessors are Goddard’s Ice, Cloud, and land Elevation Satellite (ICESat) and airborne Land, Vegetation and Ice Sensor, known as LVIS, which is flown on high-altitude aircraft to measure forests, land topography, ice sheets, glaciers and sea ice. GEDI is scheduled to be completed in 2018. NASA’s Earth Venture Instrument program is part of the Earth System Science Pathfinder program, managed by NASA’s Langley Research Center in Hampton, Virginia, for NASA’s Science Mission Directorate. The GEDI team includes co-investigators from Goddard; Woods Hole Research Center, Woods Hole, Massachusetts; the U.S. Forest Service, Ogden, Utah; and Brown University, Providence, Rhode Island.
taken from (http://www.nasa.gov/content/goddard/new-nasa-probe-will-study-earth-s-forests-in-3-d/#.VRa1sfmUcZx)
