Effects of lidar point density on bare earth extraction and DEM creation

ABSTRACT Data density has a crucial impact on the accuracy of Digital Elevation Models (DEMs) created from airborne LIDAR surveys. In this study, DEMs were created from a very high point-density LIDAR dataset using the bare earth extraction module available with the commercial product, Quick Terrain Modeler. To simulate lower pointdensity LIDAR collects, decreasing percentages of points were randomly selected from the original high-density dataset. The DEMs created from the lower point-density datasets are compared to the original DEM. Results are shown indicating the decrease in DEM accuracy as the resolution of the LIDAR dataset is reduced. Some analysis is presented on the type of errors encountered in the lower resolution DEMs. Although specific details about the bare earth extraction algorithm used in Quick Terrain Modeler were not available, it is shown that the percentage of points classified as bare earth decreases as the resolution of the LIDAR dataset is reduced