Forest mapping and trunk parameter measurement on slope using a 3D-LIDAR

This study aims to make accurate measurement of trees on a forest slope using 3D-LIDAR. The authors previously developed a mobile 3D-LIDAR with a wide field of view. The point clouds of trees are acquired using a mobile 3D-LIDAR carried in the backpack of an operator walking through the forest. 3D forest maps are generated by LOAM, which performs 6DOF matching using rotating 2D scans, and diameter at breast height (DBH) and trunk location are then measured from this 3D forest map. Point clouds at around the breast height are extracted by calculating the height at the base of a tree, the DBH is calculated by cylinder fitting of the extracted point clouds, and the trunk location is calculated using the intersection of an approximate plane of the subject area and the central axis of the trunk. Measurement precision of DBH and trunk location are evaluated on a forest slope, and results show that the precision required in forestry practice is achieved.