Comparative Accuracy Assessment of Orthophotos Produced Using Different UAV and Photogrammetric Software

This chapter explores the comparative accuracy of orthophotos produced using different Unmanned Aerial Vehicles (UAVs) and photogrammetric software. It begins by discussing the fundamental principles of photogrammetry, highlighting its advantages in terms of mobility, flexibility, and the ability to capture temporal changes. The chapter then delves into the specifics of UAV photogrammetry, which offers a cost-effective alternative to traditional aerial photogrammetry and enables real-time applications. The study focuses on the accuracy of orthophotos generated from images captured by two different UAV models, the DJI Phantom 4 Pro and DJI Inspire 1 V2, at varying altitudes. The orthophotos were processed using three different software tools: Agisoft Metashape, Pix4D, and 3Dsurvey. The chapter provides a detailed methodology, including the establishment of ground control points (GCPs) and the use of Structure From Motion (SFM) techniques to create point clouds, digital elevation models (DEMs), and orthophotos. The results are analyzed using Root Mean Square Error (RMSE) values, revealing the strengths and limitations of each software and UAV combination. The chapter concludes with a discussion on the practical implications of the findings, emphasizing the potential of UAV-based photogrammetry in achieving high positional accuracy with reduced labor and costs. The detailed comparative analysis and practical insights make this chapter an essential read for anyone interested in advancing their knowledge of UAV photogrammetry and its applications.