Authors | Dubayah R, Blair JB, Bufton JL, Clark DB, JaJa JF, Knox R, Luthcke SB, Prince S, Weishampel J |
Abstract | The Vegetation Canopy Lidar (VCL) is the first selected mission of NASA’s new EarthSystem Science Pathfinder program. The principal goal of VCL is the characterization of the
three-dimensional structure of the earth; in particular, canopy vertical and horizontal structure
and land surface topography. Its primary science objectives are: landcover characterization for
terrestrial ecosystem modeling, monitoring and prediction; landcover characterization for climate
modeling and prediction; and, production of a global reference data set of topographic spot
heights and transects. VCL will provide unique data sets for understanding important environ-
mental issues including climatic change and variability, biotic erosion and sustainable landuse,
and will dramatically improve our estimation of global biomass and carbon stocks, fractional
forest cover, forest extent and condition. It will also provide canopy data critical for biodiversity,
natural hazard, and climate studies. Scheduled for launch in early 2000, VCL is an active lidar
remote sensing system consisting of a five-beam instrument with 25 m contiguous along track
resolution. The five beams are in a circular configuration 8 km across and each beam traces a
separate ground track spaced 2 km apart, eventually producing 2 km coverage between 65° N and
S. VCL’s core measurement objectives are: (1) canopy top heights; (2) vertical distribution of
intercepted surfaces (e.g. leaves and branches); and, (3) ground surface topographic elevations.
These measurements are used to derive a variety of science data products including canopy
heights, canopy vertical distribution, and ground elevations gridded monthly at 1° resolution and
every 6 months at 2 km resolution, as well as a 2 km fractional forest cover product.
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