Abstract
Airborne laser scanning has become an established tool for generating digital terrain model (DTM) . To obtain DTM in the vegetative area, laser-reflected points on the canopies should be filtered out from digital surface model (DSM) . The filtering is automatically and manually performed, but it is difficult to obtain the perfect DTM, especially in the vegetative hills or mountain areas. In this study accuracy of the“DTM”, which was obtained in the winter of December 2001 and 2002, is validated with ground control points, surveyed by traversing. As a result, root mean square errors (RMSE) are about 0.15m and 0.4-0.6m in the bare flat areas and vegetative slope areas, respectively. Moreover, penetration ratio which is defined by the number of reflected points in DSM divided by the number in DTM, was examined with the RMSE. It was found that the more the penetration ratio increases, the smaller the RMSE is.
