Global Ecosystem Dynamics Investigation (GEDI, pronounced ) is a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

mission to measure how

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

has contributed to atmospheric CO₂ concentrations.NASA probe will reveal 3D architecture of forests from space
. Richard Moss, ''New Atlas''. 14 September 2014. A full-waveform

LIDAR Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...

was attached to the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

to provide the first global, high-resolution observations of forest vertical structure. This will allow scientists to map

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s and

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

, particularly in the tropics, providing detail on the Earth's

carbon cycle The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycl ...

.NASA has a plan to take the most detailed scans of the world's forests ever
. Pierre Bienaimé, ''Business Insider - UK''. 3 March 2015. The Principal Investigator is Ralph Dubayah, at the

University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public land-grant research university in College Park, Maryland, United States. Founded in 1856, UMD is the flagship institution of the Univ ...

. The Deputy Principal Investigator & Instrument Scientist is J. Bryan Blair at NASA's

Goddard Space Flight Center The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately northeast of Washington, D.C., in Greenbelt, Maryland, United States. Established on May 1, 1959, as NASA's first space flight center, GSFC ...

. __TOC__

Overview

GEDI was competitively selected as a NASA Earth Ventures Instrument (EVI) mission in 2014. Cost-capped at $94 M, GEDI is led by the

in collaboration with NASA

Instrument

geodetic

Lidar Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...

Using an 80 cm telescope attached to the bottom of the instrument, GEDI will be able to receive the pulses of light that bounce back from the Earth' surface and collect information on the 3D structure of the area in question. Upon the optical bench, the instrument contains three Beam Dither Units (BDU), three beam expanders, three star trackers, and three HOMER lasers. The three HOMER lasers built and installed on GEDI were built by D. Barry Coyle, Furqan L. Chiragh, and Erich A. Frese. The GEDI instrumentation is designed to collect data between 51.6° N latitude and 51.6° S latitude. Within this area, GEDI gathers data from approximately four percent of the Earth's surface, including both tropical and temperate forests. The LIDAR system can only operate effectively over relatively cloud free areas. Dense cloud cover blocks the laser pulses and prevents accurate measurements. GEDI uses an active across-track pointing system in order to help show area that is not normally covered due to the

's orbit pattern. These occur because the ISS is not maintained in a repeating orbit and can get stuck in orbital resonances that essentially repeat orbital tracks and result in large coverage gaps.

References

{{Satellite and spacecraft instruments Kibo (ISS module) Satellite meteorology SpaceX payloads contracted by NASA Spacecraft instruments Lidar Deforestation 2018 in spaceflight Earth satellite laser altimeters