基于三维激光点云数据的树冠体积计算方法研究

Research on Tree Crown Volume Calculation Method Based on 3D Laser Point Cloud Data

针对目前树冠体积计算方法存在的问题,如树冠空隙无法剔除、提取树冠边界粗糙等,本文提出了一种基于改进α-shape算法的树冠体积计算方法,通过设置最优分层间距与迭代步长实现树冠体积的精确计算。本文提出改进α-shape算法的树冠体积计算步骤为:首先对原始树冠点云进行等间距切片,并根据改进α-shape算法提取点云切片多边形边界;其次根据切片面积与分层间距实现台体体积计算,树冠最终体积为台体体积之和。通过实测树冠点云数据进行实验,结果表明本文提出算法计算树冠体积较体元法与Graham算法的稳定性更高,受树冠密度的限制更小。

Aiming at the problems existing in the current calculation methods of tree crown volume,such as the inability to eliminate the gaps in the tree crowns,the extracted rough crown boundaries,etc.,this paper proposes a tree crown volume calculation method based on the improved α-shape algorithm,which realizes the accurate calculation of tree crown volume by setting the optimal layering spacing and iterative step length.In this paper,the steps to calculate the crown volume by the improved α-shape algorithm are as follows:firstly,we slice the original crown point cloud at equal intervals and extract the polygon boundary of the point cloud slices by the improved α-shape algorithm.Secondly,the platform volume is calculated according to the slice area and the layered spacing.The final volume of the crown is the sum of the platform volumes.The experimental results of the measured crown point cloud data show that the algorithm proposed in this paper is more stable than the volume element method and Graham algorithm and is less restricted by the crown density.