“…When the photogrammetric imagery does not contain georeferencing information or ground control points (GCP), a few corresponding ALS point clouds were used as GCP information within the photogrammetric bundle block adjustment (BBA). This step was carried out because the quality of combining multi-source point cloud depends on inter-dataset registration and with regards to the LiDAR and DIM data processing chain, this registration can be categorized into four different groups (Toschi et al, 2021): (i) separate ALS stripe adjustment (SA) and bundle block adjustment (BBA), (ii) within the photogrammetric BBA use of ALS point clouds as ground control information (Yang et al, 2021), (iii) establish the transformation by using standard features (e.g., edges, boundaries, corners and 3D planar surfaces) (Peng et al, 2019), (iv) a single hybrid adjustment process with an integrated SA and BBA (Haala et al, 2020;Glira et al, 2019). Therefore, following the second category, a few corresponding ALS point clouds were used as GCP for DIM generation.…”