期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2010
卷号：XXXVIII Part 4
出版社：Copernicus Publications
摘要：Full-waveform LiDAR is an active remote sensing technique that provides the scattering properties of the targets i.e. amplitude and echowidth (EW) in addition to 3D point clouds. The amplitude provides information on the target's reflectance and the EW is a measure forthe range variation of scatterers within the laser footprint contributing to a single echo and is, therefore, an indicator for surfaceroughness. For the delineation of high vegetation (i.e. trees and bushes) and buildings the normalized digital surface model provides themain input. Based on a height threshold, areas covered with elevated objects can be classified. For the differentiation between buildingsand high vegetation the surface roughness is used, where roofs are assumed to be smooth and vegetation rough. The surface roughnesscan be described with the standard deviation (SD) of detrended LiDAR points. However, for low LiDAR point densities and for verydense deciduous forests or building parts overgrown with tree crowns the separability is limited if only the SD is used. Within thepresented approach additionally the EW, featuring small values for smooth roof areas, and the echo ratio (ER), a measure for thepenetrability of a surface, are used. For the final delineation of high vegetation and building areas morphologic operations are applied.The classified areas are vectorized and a minimum mapping unit is applied. The presented workflow is implemented into the scientificsoftware package OPALS (Orientation and Processing of Airborne Laser Scanning data). The results show that the EW, the SD and theER are useful quantities to delineate high vegetation and building polygons based on full-waveform LiDAR point clouds with highaccuracy. The high degree of automation and the scripting capability OPALS promise a high potential for operational large area LiDARdata processing. Examples from different test sites in Austria are shown and discussed
关键词：Three-dimensional; LIDAR; Retrieval; Roughness; Land Cover; Full-Waveform
