基于三维激光扫描点云的树冠体积计算方法  

Tree Crown Volume Calculation Based on 3-D Laser Scanning Point Clouds Data

作　　者：韦雪花[1] 王永国[2] 郑君[1] 王萌[1] 冯仲科[1] 

机构地区：[1]北京林业大学林学院,北京100083 [2]北京市测绘设计研究院,北京100038

出　　处：《农业机械学报》2013年第7期235-240,共6页Transactions of the Chinese Society for Agricultural Machinery

基　　金：北京市自然科学基金资助项目(4091002)

摘　　要：针对树冠形状不规则,树冠体积难以测量和计算的问题,提出一种基于三维激光扫描点云的树冠体积计算方法——体元模拟法,即以固定大小的体元模拟不规则的树冠形状。首先将树冠沿树高方向以k为步长进行等距离分段,把每一段树冠的点投影到垂直于树高方向的平面上,再对该平面划分成大小为k×k的像元,根据投影到各个像元内点的数量,判断该像元的有效性,统计有效像元的数量T,则树冠体积为T个k×k×k的体元之和。经试验,当体元边长等于冠径的1/10时,计算的树冠体积达到稳定。该算法对于任何树种不用考虑树冠的形状,减少了人为判别导致的差异,适用于三维激光扫描树木树冠体积的计算。The tree crown volume is difficuh to measure and calculate because of its irregular shape. A calculating method of tree crown volume, named voxel simulation method, was presented based on 3-D laser scanning point clouds data. The main idea of this method was to use a certain size of voxel to estimate tree crown. Firstly, tree crown was cut into segments with a k step-length along tree height. For each segments, all the points were projected to a plane that perpendicular to tree height. Subsequently, the plane was divided into pixels with size of k×k. The effectiveness of each pixel depend on whether there were points projected in it. Then the effective pixels were counted and recorded as T. Finally, formula T × k×k×k was used to calculate the tree crown volume. When the k was equal to a tenth of crown diameter, the calculated crown volume was tending to stability. This algorithm did not need to consider the crown shapes of different tree species, which could reduce human＇s subjective factor influence. It could be used to calculate tree crown volume based on 3-D laser scanning technology.

关 键 词：树冠体积 体元模拟法 三维激光扫描 点云 

分 类 号：TN249[电子电信—物理电子学] S758.1[农业科学—森林经理学]