NASA mission to measure the carbon content of the Earth’s forests

The Laser Vegetation Imaging Sensor (LVIS) has mapped eastern US forests in Maryland, North Carolina and New Hampshire as well as California’s Sequoia National Forest and Costa Rica’s tropical rainforest in order to calibrate and validate the equipment before it is launched aboard the NASA/University of Maryland Vegetation Canopy Lidar (VCL) spacecraft, due to enter space in September 2000.

“The whole point of the space mission is to provide a baseline of the Earth’s forests,” Dr Ralph Dubayah, associate professor at the geography department at the University of Maryland, told edie.

According to Dubayah, the data will provide the first accurate information regarding the carbon content of the Earth’s forests. Such data will allow for a better understanding of the true amount of CO² released into the atmosphere from deforestation. Dubayah sees the data as a potential tool for verification of nations’ Kyoto Protocol CO² reduction achievements.

LVIS employs sensor technology that has been used to map the surface of Mars and coastal erosion on Earth. An adaptation of the technology has been achieved to map the ground beneath dense forests and the structure and density of forests themselves.

Five lasers send pulses to the Earth’s surface resulting in photons bouncing off leaves, branches and the ground. The photons reflect back and the returned signals provide information on the height of the forest canopy and the density of vegetation.

The VCL spacecraft will launch from Alaska’s Kodiak Launch Complex in September 2000. The mission is scheduled to last 18 months, although there will be fuel to last two years. The length of the mission will depend on the stamina of the lasers, which deteriorate over time.

Data from the mission will be distributed by the US Geological Service and, according to Dubayah, data will be affordable and available to anyone. “We’ll release the first data sets seven months after launch. Then anybody can have access to the data,” he said.

The project is part of NASA Earth Systems Science Pathfinder programme. “The idea behind the programme is to have cheap missions that answer important questions about the Earth,” explained Dubayah. The VCL mission is led by the University of Maryland in collaboration with NASA Goddard’s Laboratory for Terrestrial Physics.