Determination of terrain models in wooded areas with airborne laser scanner data

Large-scale terrain measurement in wooded areas was an unsolved problem up to now. Laser scanning solves this problem to a large extent. In this article, the-characteristics of laser scanning will be compared to photogrammetry with reference to a big pilot project. Laser scanning supplies data with a skew distribution of errors because a portion of the supplied points is not on the terrain but on the treetops. Thus, the usual interpolation and filtering has to be adapted to this new data type. We will report on the implementation of this new method. The results are in accordance with the expectations. The geomorphologic quality of the contours, computed from a terrain model derived from laser scanning, needs to be improved. Solutions are still to be found. (C) 1998 Elsevier Science B.V. All rights reserved.