标题：ACCURACY OF TREE HEIGHT ESTIM ATION USING LIDAR DATA-DERIVED DCM
其他标题：DOKàADNOĝû OKREĝLENIA WYSOKOĝCI DRZEW NA PODSTAWIE NUMERYCZNEGO MODELU KORON DRZEW OPRACOWANEGO Z WYKORZYSTANIEM DANYCH LOTNICZEGO SKANOWANIA LASEROWEGO
期刊名称：Archiwum Fotogrametrii, Kartografii i Teledetekcji
印刷版ISSN：2083-2214
出版年度：2008
卷号：18
语种：English
出版社：Main Board of Association of Polish Surveyors
摘要：The tree height of a forest stand is a crucial parameter determining a forest space. In this paper,results of a study aimed at extracting the height of individual trees using only LIDAR data are presented. The study focused on the Gluchow forest owned by the Warsaw University of Life Sciences (SGGW). Laser data were acquired twice – in spring and in summer. The laser-sampling density was approximately 6 points/m2 . An unsophisticated algorithm for DSM generation,using the first laser impulse,was developed. DTM generation,i.e.,extraction of points belonging to the topographic surface from point clouds formed an important part of the study. Two filtering methods: the FFT-based frequency analysis and the adaptive TIN model were used. The accuracy analysis of DTM and DSM was performed at two test sites. The filtering algorithms were found to have some limitations. The largest errors were detected for areas with low,dense vegetation,which were completely classified to topographic surface. It was necessary to correct the results and eliminate the incorrectly classified points. Heights of individual trees were determined using only laser data. At the first test site satisfying results were produced by using the simple method of subtracting DTM from DSM. The calculated tree heights were compared with check point data collected during a high-accuracy topographic survey. The mean deviation of -0.456 m was completely sufficient. The other test site was more complex and required more advanced methods of analysis. At the first step,a digital crown model (DCM) was calculated by subtracting DTM from DSM. DCM was smoothed by a Gaussian filter. The following step involved segmentation of the watershed to estimate crown areas. The heights of individual trees was determined as the local maxima. These values were compared with the check point data,whereby a mean deviation equal to –0.273 m was obtained. To conclude,the results of this study demonstrated lidar data to have a high potential for use in tree height estimation.
其他摘要：WysokoĞü drzew i drzewostanu jest waĪnym elementem opisującym przestrzeĔ leĞną. W artykule przedstawiono wyniki badaĔ nad zastosowaniem danych skanowania laserowego do wyznaczania wysokoĞci pojedynczych drzew. Badania prowadzono na powierzchniach próbnych
