Testing the accuracy and characteristics of data acquired using DJI Zenmuse L1 and L2 lidar systems and photogrammetric data acquired using DJI Zenmuse P1 in a quarry environment

The present study aimed to compare the performance of the DJI Zenmuse L2 lidar scanner for unmanned aerial vehicles (UAV) with that of the previous generation of the same system (DJI Zenmuse L1) and a cloud derived by photogrammetry (DJI Zenmuse P1) in a quarry area. A reference cloud was acquired using a terrestrial laser scanner Leica P40. The results show a major improvement in the L2 accuracy compared with the older L1 scanner, particularly where the overall accuracy after smoothing (RMSES = 0.03 m for L2, compared to 0.05 m for L1) and noise (RMSENOISE of 0.026 and 0.045 m for L2 and L1) are concerned. Color displacement, however, remained practically identical between L1 and L2, reaching a maximum of almost 0.35 m. The accuracy of the photogrammetric point cloud was still somewhat better than the new generation L2 scanner (RMSEO = 0.017 m); however, where practical applicability is concerned, the accuracy provided by the new generation lidar scanner is sufficient for a vast majority of applications and considering other advantages of lidar over photo-grammetry, the new generation scanning technology has the potential to replace photogrammetry in the acquisition of point clouds using UAV in the foreseeable future.