Object-based analysis of airborne laser scanning data for natural hazard purposes using open source components

Geoinformation is an important basis for planning strategies, natural hazard modelling, process detection, and risk analysis. Airborne Laser Scanning is an operational working method for area wide data acquisition and provides 3D information in a high spatial resolution. The data contains detailed information to characterise surface properties which is, however, not obvious to extract from the massive cloud of points or elevation raster. Object-based analysis allow to obtain additional information for surface classification. The following paper presents the current status of work for determining surface properties and object classification. The workflow for object-based analysis of Airborne Laser Scanning data is integrated in the Open Source GRASS GIS environment using the implemented image processing and standard GIS functionalities. Two examples show the classification of "raised" objects and the detection of geomorphologic structures in Airborne Laser Scanning elevation data.