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：1999
卷号：XXXII-3/W14
出版社：Copernicus Publications
摘要：The major factors a.ecting the accuracy of Airborne Laser Scanning (ALS) systems are the errors in ranging, in the position of the laser firing point, and in the attitude of the laser beam. Since the derivation of a precise theoretical accuracy model is rather complicated, accuracy estimates are mostly obtained by comparing Digital Elevation Models (DEMs) derived from laser scanning with reference DEMs. This technique works well on .at or gently sloping terrain, however it is not suitable for complex 3D terrain. For example, small displacements of the laser footprints can cause large elevation errors around tall buildings. Large range errors can occur when the elevation or brightness varies within the footprint, such as along the boundaries of buildings, or around trees. Moreover, other non-sensor related factors, such as the point distribution, the post-processing algorithms, and the extracted features also e.ect the accuracy. We first present a general quality control scheme, followed by analyzing the accuracy of ALS over urban terrain. The analysis is performed low altitude aerial photographs. First, a reference DEM was measured from the aerial photographs on the analytical plotter. To facilitate the visual comparison between the reference DEM and the surface points from ALS, both the reference DEM and the laser points were back-projected onto the aerial stereo photographs. The di.erences between the two surface descriptions were obtained in the classical way by comparing the laser points with the reference DEM. This standard approach is not suitable in areas of large elevation changes. A better way to compare the accuracy is to extract features and to compare them. We compare planar surface patches and 3-D lines obtained from intersecting planes
