A study of subtropical forest structure using high density airborne lidar data

Airborne lidar system is becoming an effective tool for tree crown identification and canopy mapping. This study involves the examination of tree position depicted by digital surface model and canopy height model derived from lidar point cloud of a subtropical forest. Due to the complex structure of the forest, little of the lidar point arrives at the ground. It is expected that the lidar point data density has significant effect on the accuracy of tree position determined from the point data. To verify this, a lidar data with an averaged point density of 276 points/m ² was obtained and the point density was randomly thinned to 1, 5, 10, 20, 30, 40, 50, and 100 points/m ². The results of the tree positions were compared to that using a FARO Photon 120 terrestrial laser scanner.