A Method for Estimating Timber Volume for Single Tree Units by Combination of UAV Images in Forest and UAV Laser Data

Abstract

Estimating the timber volume is effective in grasping the amount of carbon dioxide absorbed by the forest clearly. However, it is laborious and dangerous for staff to estimate the timber volume by using vernier caliper and ultrasonic tree height measuring instrument. Therefore, we have developed a system that can conduct timber volume estimation automatically by using a small unmanned aerial vehicle (UAV) equipped with camera and a lidar. In this research, we propose a registration method of point cloud generated by images acquired under GNSS invisible conditions and laser data from sky. The experimental results show that our system could estimate the trunk diameter within ± 2.11 cm (RMSE).