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标题：Determination of Urban Vegetation Volume on the Basis of Laser-Scan Data at Non-Leaf Aerial Flight Times
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作者：G. Meinel ; R. Hecht
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：2004
卷号：XXXVI-8/W2
出版社：Copernicus Publications
摘要：The determination of urban vegetation volume is getting more and more important within the frame of an ecologically orientated city planning. Conventional methods like the height categorization of typical kinds of vegetation followed by multiplication with the area are costly and complicated during survey but remain exact. Since there are several cities which already have laser scanner data for creating 3-D city models the idea emerges of using this data for the determination of urban vegetation volume. It is a problem that the date of survey of Digital Elevation Models (DEM) is not within the vegetation period and therefore interferes considerably with the survey of the vegetation volume. That's why this paper deals with the question whether laser scanner data that has not been taken during the vegetation period allows a determination of vegetation volume with sufficient accuracy . Therefore laser scanner data has been compared to photogrammetrically determined vegetation height measurements. Despite a relatively high laser point density of one point per m2 it has to be considered that almost 80 % of the measurement points in the vegetation stock have been classified as ground points because the non-leaf tree branches have led to insufficient reflections . Even with the measurement data classified as non-ground points, the vegetation height has been underestimated by approximately 50 % on average. Thus the subtraction of the laser-based Elevation Model (DEM) and Surface Model (DSM) in vegetation areas leads to a sufficient underestimation of vegetation volume of up to 85 %. By applying correcting methods this error is to be corrected and might lead to a sufficiently exact and efficient determination of vegetation volume on the basis of laser scanner data of aerial flight times during non-vegetation periods. The necessary separation of a vegetation-covered area and an area with no vegetation can be carried out with the urban geo-basis data or from the color infrared film with the NDVI