Abstract
This paper presents the result of lost rural landscape reconstruction with high fidelity using GIS technologies. The U.S. air force aerial photographs, 1/3,000 scale topographic map published from a local government, and 1/25,000 scale topographic map published from the national mapping agency were used as primary materials for the reconstruction. The process of the study is as follows. The positional accuracy of the primary materials was validated. Then, grid type DEMs were created from each material. We tested both a precise method and a simplified method as the image ortho-rectification method. The former one utilized the aerial triangulation result and the latter one employed the affine transformation. Bird's-eye views were created from combinations of DEMs and colorized ortho images. Small terrain undulations and levees were expressed on the DEM created from aerial photographs, although they were lacked on the DEMs from topographical maps. It says that the aerial photographs are best from the perspective of precision. The aerial triangulation, on the other hand, is much cost consuming. The comparison of image ortho-rectification methods revealed that the simplified method created relatively large displacement at a hill top. We compared bird's-eye views created from different materials. There was little difference between them at the zoom out view whereas the quality of scene was proportional to the quality of DEM at the close up view. The combination of DEM and ortho image from the aerial triangulation result made the better scene as the terrain undulations harmonized with land cover classifications. As a whole, it is best to utilize aerial photographs in both DEM generation and ortho rectification process. However, the time and the cost needed for the process is the highest of all. The required accuracy and availability of materials must be considered when choosing the method.
