Fig. 5

Point clouds of example trees inside and outside the effective area. The left subfigure marks the locations and the labels of example trees. The right subfigures illustrate the point cloud of the example trees, and the colors of points represent different segments of the trajectory with respect to the platform directions. Green represents the points from the above-canopy flight, other colors are from the under-canopy flight; Labels of the example trees in the left and right figures are correspondent. a Is a tree that was well digitized from all directions (scanned three times from different directions); b Is a tree inside the effective area that was regarded as DBH not measurable by the operator, but was detected and modeled by the automated method; c Is a tree at the border of the effective area; and d is a tree located outside the effective area and with a similar size as the tree in a. Points of tree d mainly come from the above-canopy flight