Method of visualizing landscapes from tombs of the Final Kofun period with a high-definition three-dimensional model by SfM and three-dimensional GIS: A case study of three tombs in the Kawachi area

We visualized landscapes from three tombs of Japan’s Final Kofun period (the latter part of the 6th century through the end of the 7th century) in the Kawachi area (Kannonzuka, Hachibuseyma-nishimine, and Okameishi Tombs) with a high-definition three-dimensional model by structure from motion (SfM) multi-view stereo photogrammetry and three-dimensional GIS to analyze the relationship of the axial directions of the tombs and their views. We clarified the following points: 1) By SfM with photographs from an unmanned aerial vehicle (UAV), we generated georeferenced digital surface models (DSMs) with about 1-cm resolution and orthophotos with about 0.5-cm resolution to express the microtopography of the three tombs. 2) We overlaid DSMs and orthophotos by SfM on a 5-m digital elevation model (DEM) and orthophotos by GSI using three-dimensional GIS and visualized landscapes from the three tombs at that time, although their views are now obstructed by trees. 3) Considering the surrounding obstacles, shooting photos with a manual pilot is more suitable than with an auto pilot for reproducing the shapes of the stones and the tomb mounds.