Monitoring forests at the speed of light.

Abstract

Airborne laser scanning is a technology developed in the last 15 years. Commonly referred to as light detection and ranging, or LIDAR, these systems can map ground with up to a 6-inch elevation accuracy in open, flat terrain. LIDAR is being rapidly adopted for topographical and flood-plain mapping and the detection of earthquake faults hidden by vegetation, among other uses. Most analysis begins with a process known as "bare-earth filtering"—laser scan data about trees and buildings are stripped away to leave just the bare-ground data. These discarded data, however, are extremely valuable for many forestry uses.

Scientists from the Pacific Northwest (PNW) Research Station and University of Washington, along with other partners, have been using LIDAR data to describe vegetation. In just the last 5 years, scientists have discovered that LIDAR can characterize the forest along with the contours of the land, providing accurate data on forest characteristics such as canopy height, stand structure, growing-stock estimates, wildlife habitat, and biomass.

LIDAR can be a revolutionary technology in forestry. Although LIDAR will never replace getting out on the ground, data that used to be available only for a few plots or selected stands may be routinely available for an entire forest, currently at a cost of about $1 to $2 per acre. In a few years, the use of LIDAR scans may be as commonplace as the use of aerial photos and topographic maps today. Learn more inside about how LIDAR works and what it offers.

Citation

Rapp, Valerie. 2005. Monitoring forests at the speed of light. Science Update 12. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 12 p.