ABSTRACT
Laser scanning is an active remote sensing technology operated from airborne and terrestrial platforms for directly measuring three-dimensional coordinates of points on surfaces, including the terrain and objects thereupon (e.g. trees or houses). In literature often the term airborne LiDAR (= Light Detection And Ranging) is used synonymously. Airborne laser scanning is becoming the standardmethod for acquiring area-wide topographic data replacing image-based photogrammetry as it has numerous advantages. First of all, airborne laser scanning operates with high degree of automation, from data acquisition to digital terrain model generation, which has a positive effect on data processing costs. The measurements can be made with high density (1 point/m2 or higher as a standard value) and with a vertical accuracy (ca. ±10 cm), which allows a very detailed terrain representation. Airborne laser scanner signal has also the ability of penetrating through vegetation cover and thus recording the ground surface also in wooded areas, which obviously is not relevant to glacier studies. As laser scanner system is an active system, the direct measurement allows data acquisition during night or over areas with very limited texture (e.g. snow surfaces). The ability to acquire information from snow surfaces is probably the most important advantage in glacier studies. The original idea of using airborne laser scanning technology in OMEGA was to apply and evaluate airborne laser scanning as a stand-alone method for different tasks in glaciological research. A further intention was to provide a benchmark topographic dataset against which datasets derived from other remote sensing technologies could be tested. In particular, additional interest was laid in investigating further possible applications of airborne laser scanner data which goes beyond the simple provision of high resolution digital elevation models.
