The NASA/University of Maryland Vegetation Canopy Lidar (VCL) mission will create the first maps of the three-dimensional structure of vegetation in the world's forests. VCL is scheduled for launch in September 2000. The mission is the first selected program of NASA's Earth System Science Pathfinder project.

Science Objectives
VCL has two primary scientific goals. On the local and regional scale, VCL maps will provide new measurements of the age and condition of forest ecosystems. They will increase by 200,000 times the area of tropical land surface surveyed. On a global scale, VCL maps provide an inventory of forest biomass and new measurements of the texture of the Earth's land cover, a critical factor used in climate modeling and weather prediction.

Previous satellites have mapped vegetation area in great detail, but VCL will be the first to map the vertical dimension of a forest. Where the leafs and twigs and branches are within a forest— how much is high in the canopy or near the ground in foliage—changes as a forest ages. These maps will provide a direct way to identify degraded areas, areas of regrowth, and intact forests. Biodiversity studies can use VCL's comprehensive assessment of forest structure and organization to identify and monitor important habitat areas.

VCL will yield a 5-10 times improvement in estimates of forest canopy height, a measurement used to estimate total biomass. Biomass in forests represents the major reservoir of carbon in terrestrial ecosystems that can be quickly released by disturbance (such as wildfire) or land use change.

Climate and weather forecasting models use approximations of surface cover in their calculations because the movement of the atmosphere and weather systems are influenced to some degree by the "texture" of land cover. Current estimates of surface cover, however, are based on very little data. VCL's direct measurements of canopy height and density over much of the world will be used in these models to represent more accurately the aerodynamic properties of the Earth's surface.

Mission Overview
Over its two-year lifespan, VCL will sample the vast majority of the Earth's closed canopy forests, from 65 degrees North latitude to 65 degrees South latitude. The spacecraft will be launched into a 260-mile-high orbit from Alaska's new Kodiak Launch Complex. The University of Maryland Geography Department will house VCL command-and-control and data processing operations.

next: A New Application of Lidar Technology

Vegetation Canopy Lidar
Science Objectives
A New Application of
Lidar Technology
Applications to Forest
Management Needs
Lidar Lasers:
A Safe Technology

Top Left: The Vegetation Canopy Lidar (VCL) satellite. Due to launch in the fall of 2000, VCL will provide information about the age, density, and complexity of forests around the world. (Image by Eric F. Pfleckl, Orbital Sciences Corporation)

Bottom Left: The Laser Vegetation Imaging Sensor (LVIS), flown aboard an aircraft, helped test the technologies to be used in VCL. (Image courtesy NASA GSFC Scientific Visualization Studio)