Research on the Construction Method of 3D Tree Model Based on Laser Point Cloud and Tree Radar
Zhang,Ruiling&#65288-a*&#65289-&#12289-Wang,Muzi(a)&#12289-Dong,Youqiang(a)&#12289-Wang,Xinhao(a)&#12289-Yin,Keru(a)

(a)School of Geomatics and Urban Spatial Informatics, Beijing University of Civil Engineering and Architecture, China
* 1108140522004[at]stu.bucea.edu.cn

Abstract

In view of the fact that it is difficult to quantify the degradation of mechanical properties caused by internal cavitation decay in traditional tree morphology modeling, it is impossible to characterize the anomaly of mass distribution and stiffness attenuation. In this study, a three-dimensional modeling method based on multi-source data fusion of laser point cloud and tree radar was proposed. Firstly, based on the high-precision defoliated point cloud, the KD-Tree spatial index was used to accelerate the proximity search and the Dijkstra algorithm to extract the tree skeleton line, and the segmented cylinder fitting modeling of the branch was realized through the cross-section centroid positioning and geometric parameter calculation. Secondly, the tree radar reconstructs a two-dimensional cross-sectional image at the corresponding height by using the physical characteristics of electromagnetic waves with slower propagation speed and enhanced attenuation in the decay region, showing the distribution difference between the internal air decay and the intact wood area. Image segmentation and density-weighted centroid estimation were carried out on the two-dimensional cross-sectional image to accurately identify the true centroid position of the cavitation area. Finally, through the highly hierarchical and directional registration technology, the cavitation data was mapped to the 3D model, the centroid offset vector caused by cavitation was calculated, and the local volume was deducted on the model to realize the correction of the mass distribution of the model. Experiments are carried out on a variety of tree species, and the results show that the proposed method can synchronously integrate external geometric features and internal decay information, providing a high-precision structural basis for tree mechanics simulation and risk assessment. Compared with the traditional modeling method, this method can more truly reflect the influence of mass distribution and local defects on the overall structure, and has good adaptability and promotion potential.

Keywords: laser point clouds-tree radar-3D modeling- data fusion

Topic: Topic C: Emerging Technologies in Remote Sensing