Airborne LiDAR Applications in Forest Landscapes

Abstract

This chapter provides an introduction and overview of using light detection and ranging (LiDAR) in forest applications. The first section explains the principles and basic terminology for LiDAR and introduces the use of LiDAR on three different platforms (spaceborne, airborne, and terrestrial) for forest applications. The second section discusses applications in relation to the primary measurements from a LiDAR point cloud, primarily information derived from distance (from the aircraft to the target). We cover concepts related to different representations of surfaces (e.g., digital surface model, digital terrain model, digital elevation model, and canopy height model). Typically, single trees can be identified from the canopy height model and there are two different ways to assign LiDAR points to individual trees, the surface-based method and the point-based method. The third section discusses forest applications in relation to secondary measurement from a LiDAR point cloud, information derived from point cloud geometry rather than direct distance measurements. This section covers tree genera classification; the use of allometric equations for deriving DBH, biomass, and other forest attributes; and the classification of vegetation types. Three ways of getting genera information are discussed, including the vertical profile method, methods relying on geometry derived from individual tree point clouds, and methods that incorporate spectral information. The fourth section provides a case study for identifying potential tree hazards along a powerline corridor in Ontario, Canada. We conclude by discussing the future of this technology.