Assessment of Digital Elevation Model (DEM) using onboard GPS and ground control points in UAV image processing

The Unmanned Aerial Vehicle (UAV) technology has evolved dramatically in the 21st century in the military and general public for the recreational purposes and mapping work. The UAV operating costs are much cheaper compared to the normal aircraft and do not require a large workforce. There are other systems that have the same function like the Light Detection and Ranging (LIDAR) and Satellite Images. These systems require a huge cost and more labors and are time consuming to produce the Digital Elevation Model (DEM). The objective of this study is to investigate the accuracy of the DEM by using commercial software such as Agisoft and Pix4D with the Ground Control Point (GCP) and onboard Global Positioning System (GPS) processing. The aim of the study is to assess the DEM based on the UAV image processing. In this study, a hexacopter UAV was used to capture aerial images from a certain altitude. The Ground Control Point and Control Point were established using the GPS static technique. There are two types of analyses in this study which are the DEM accuracy based on Residual Mean Square Error and slope percentage. As a conclusion, the UAV images have the potential to be used for updating the DEM at a specific area.