NSF NEON Lidar

Scientists often need to characterize vegetation over large regions to answer research questions at the ecosystem or regional scale. To measure vegetation or other surface features at these larger scales, remote sensing methods that can take many measurements quickly, using airborne sensors, are essential.

Lidar, or Light Detection And Ranging, is one such remote sensing method used to map ecosystem parameters, including vegetation height, density, and other characteristics across a region. Lidar directly measures the height and density of vegetation on the ground, making it an ideal tool for scientists studying vegetation over vast areas. It provides a detailed 3D picture of forest structure, allowing for inquiries into forest production and decline over time.

The lidar sensor is an active sensor, generating its own energy source, which allows for operations at night or under cloud cover. It uses a highly collimated laser beam directed toward the ground at a wavelength of 1064 nm. The reflected laser energy's two-way travel time is used to calculate the range to the point of reflection. Combined with precise aircraft position and orientation, this enables geo-location of objects in three dimensions, providing detailed sampling of the terrain.