UAV PHOTOGRAMMETRY: STRUCTURE FROM MOTION DATA EVALUATION FOR DEM APPLICATIONS

This poster describes a comparison of Digital Elevation models (DEMs) constructed using airborne LiDAR data and personal UAV (Unmanned Aerieal Vehicle) imagery. Using the structure-from-motion (SfM) software Agisoft Photoscan, stereo-imagery was processed to render a photogrammetric point cloud and DEM of a wheat field, located south of Ellensburg, Washington. LiDAR was downloaded form the USGS online data library, and used as an auxiliary assessment tool for the UAV data. The point cloud standard distance for the LiDAR was 0.65 meters, while the photogrammetric point cloud was 0.23 meters. The accuracy of the final structure from motion model ground control points illustrated an RMSE of 0.058 meters. After both separate DEM construction methods were conducted, a series of raster comparison statistics were used to identify the usefulness and accuracy of the UAV generated models. In summary, if LiDAR data is available, model construction is more time and cost effective. If higher resolution ore temporal objectives are necessary for research purposes, UAV SfM algorithms are a valuable tool that can easily supplement airborne LiDAR DEM outputs.