UJI AKURASI DALAM PEMBUATAN ORTOFOTO DAN DIGITAL ELEVATION MODEL DARI FOTO UDARA

Abstract

This study compared two numbers of Ground Control Points (GCPs), namely 8 points and 6 points, to verify the accuracy level of orthophotos and Digital Elevation Models (DEMs) created from aerial photographs using an Unmanned Aerial Vehicle (UAV). Agisoft Metashape and ArcMap 10.8 were used for data processing, and Regulation of the Head of the Geospatial Information Agency (BIG) Number 6 of 2018 was used for accuracy assessment. DJI Mavic 2 Pro drone and Comnav T300 Geodetic GPS were used in this study, which was conducted in Ilir Timur Dua District, Palembang City. The results showed that the standard of a class 1 map at a scale of 1:25,000 was met by using 8 GCPs (Ground Control Points), which resulted in a horizontal accuracy of 1.0697 m and a vertical accuracy of 5.8815 m. Meanwhile, the class 2 standard was achieved at the same scale with a horizontal accuracy of 3.9337 m and a vertical accuracy of 6.2813 m when six GCPs were used. The geometric accuracy of orthophotos and Digital Elevation Models (DEMs) is significantly influenced by the number of GCPs, as indicated by the Root Mean Square Error (RMSE) value. The resulting photogrammetric model is more stable when the GCPs are more evenly distributed. To improve the quality of UAV-based mapping products, this study offers suggestions for utilizing the ideal number of GCPs.