Evaluating the absolute accuracy of UAV RTK photogrammetry and LiDAR for 3D cultural heritage documentation: a comparative study of DJI zenmuse P1 and L1 systems

Abstract

Cultural heritage faces numerous threats, ranging from armed conflicts to the impacts of climate change. The need for robust documentation methods to safeguard and preserve cultural assets has become increasingly apparent. In this context, 3D documentation has emerged as a pivotal tool, providing a comprehensive means to capture and analyze cultural heritage in intricate detail. Various technologies contribute to 3D documentation, each with unique advantages and limitations. As technology evolves, the accessibility of high-precision methods, such as Light Detection and Ranging (LiDAR), has expanded. The main aim of this paper is to assess the absolute accuracy of the post-processing kinematic (RTK/PPK) approach of the UAV RTK LiDAR system (Matrice M300 RTK + DJI Zenmuse L1 LiDAR) with UAV RTK aerophotogrammetry (Matrice M300 RTK + Zenmuse L1 RGB and DJI Zenmuse P1 camera). Also, the comparison of reconstructed dense clouds is done using C2C and M3C2 within CloudCompare software as well as roughness analysis using the Compute geometric feature tool. The research indicates that aerial photogrammetry using the P1 camera has the highest absolute RTK/PPK approach accuracy. However, L1 RGB is accurate enough for 3D cultural heritage documentation application. Furthermore, the cloud-to-cloud comparison has demonstrated that the L1 RGB camera is more accurate (~ 5 cm) than the L1 LiDAR.