Accuracy validation of various measurement instruments for acquisition of high precision forest resource information

Matsumura, Naoto, Arita, Takahiro, Hirose, Yuki, Numamoto, Shinya, Shimada, Hiromasa and Nomura, Hisako: Accuracy validation of various measurement instruments for acquisition of high precision forest resource information. Jpn. J. For. Plann. 54: 55~61, 2020 Generally,information on DBH and height is required to determine tree size. As methods to acquire these kinds of forest information more efficiently and inexpensively, measurements with airborne LiDAR, UAV and terrestrial laser scanning（TLS）were compared.The characteristics of respective measurement methods were evaluated and efficient acquisition of forest information in the future was examined. Two types of TLS equipment with different scanning performance（Type OWL and Type FARO）were used. With TLS, which enables more direct DBH measurement, the most accurate result of the three methods was obtained, with DBH, error（Root mean square error: RMSE）=1.1 cm（Type OWL）and 1.3 cm（Type FARO）. However, as the laser is difficult to reach the tree top, the height error（RMSE）was 2.9 m（Type OWL）and 1.8 m（Type FARO）, which was larger than 1.2 m of drone photography. The comparison of worktime showed significant reduction to 1/5-1/50. Improved efficiency and cost reduction can be expected by utilizing these measuring instruments.