Point density effects on digital elevation models generated from LiDAR data

Abstract

The use of Airborne LiDAR Systems (ALS) to obtain topographical information of the earth's surface and generate Digital Elevation Models (DEMs) has grown extensively in the field of Remote Sensing. Selected areas of point cloud LiDAR data collected from Honduras in 2008 was used to produce DEMs with varying densities to show the effects of lower resolution LiDAR data. An IDL code was utilized to reduce the selected LiDAR point cloud data to 90%, 66%, 50%, 30%, 10%, 5%, 3%, 1%, 0.5%, 0.3%, 0.1%, 0.05%, 0.03%, and 0.01% of its original density to obtain lower resolution data sets. The software Quick Terrain Modeler (QTM) and its ILAP Bare Earth Extractor Plug-in was used to generate DEMs from the varying point cloud density data sets and the software ENVI was used to perform DEM analysis. It was found that LiDAR point cloud density data set of at least 0.6 points per square meter is necessary to generate an accurate Digital Elevation Model for the test environment.