Ground Surface Estimation in Dense Forest

Usually, filtering is performed in order to extract a ground surface from laser points obtained with the airborne laser scanner. It mainly removes the laser points that were measured as trees surface. However, in the dense forest where trees are grown thick, we can see the part of the laser points has not reached to the ground surface. If it conducted the filtering that sorts out the laser points in such area, the ground surface is obtained as the laser points of only coarse interval theoretically. For this reason, a correct ground surface cannot be acquired with the ordinary filtering method in dense forest. In order to solve this problem, it analyzes paying attention to the tree height map obtained by laser measurement. In the dense forest where laser beams do not penetrate partically, trees height value becomes low rapidly and it appears as a gaping hole of local tree height map. Compensation processing which interpolate this gaping hole was performed and the tree height map was estimated. This report presents the ground surface estimation method by using the interpolated tree height map obtained by using the laser scanner in dense forest. * Corresponding author.