Case Study Using LIDAR to Measure the Morphology of a Bog

Abstract

Bogs are dynamic hydrological systems. The morphology of a bog changes annually, effectively swelling during the wintertime and shrinking during the summertime, and the dynamics of the morphology must be understood to effectively support the hydroecology. The advantages of airborne LIDAR surveys are to get the morphology of a large area quickly, more easily and potentially more accurately since there is no intervention between the system and the bog surface which moves underfoot in the course of carrying out a conventional global positioning system (GPS) survey. However, bogs have a vegetated and hence a quite rough (soft) surface and the uncertainty lies in whether the LIDAR laser pulse interacts with that soft surface. The topography a raised bog was surveyed using airborne LIDAR and real time kinetic GPS systems. The LIDAR and GPS surveys were in good agreement with a maximum discrepancy of about 12 cm in the surface elevation recorded over the central plateau. The surface vegetation did not appear to have interacted unduly with the reflected LIDAR laser pulses.