Application of High-resolution (10m) Dem on Geographic Information Systems

A high-resolution Digital Elevation Model (DEM) (10m meshed grid) has been integrated with Geographic Information Systems (GIS). So far, 50m-meshed DEM by the Geological Survey of Japan (GSJ) is widely used for various GIS applications such as constructing 3D systems in Japan. 50m DEM covers all over the area of Japan, which has 0.1-meter resolution in a vertical direction. The spatial resolution of 50m DEM is, however, not enough for precise requirements from cartographic designers, developers, and civil engineers. Recently, 10m-meshed DEM has been developed by a commercial cartographic company, which also covers all over the area of Japan, and has 0.1-meter resolution in a vertical direction. The minimum unit of 10m DEM file corresponds to the second level mesh code, that is, a 1/25000 topographic map defined by GSJ, which is composed of 1000 lines by 1000 pixels. This format is quite convenient in integration with GIS. The GIS data constructed by Kitakyushu City in Kyushu area in Japan is used for the present analysis. This GIS data has many quite precise features such as not only roads, public area, etc. but also individual housing area, water supply lines. Kitakyushu City Office surveys the city area by aerial survey once for one year or two years, which takes much cost at each time. And also, an IKONOS one-meter high-resolution pan-sharpen image has been integrated with GIS at the same time. An affine transformation has been carried out to integrate an IKONOS image with GIS, in which the RMS error of 30 GCP is finally reduced to 0.4 pixels, which are quite good. Then, the IKONOS image is pasted on a surface of 3D structure constructed by 10m DEM. As a result, the detailed 3D view on a surface with an IKONOS image overlaid with roads, and another features is obtained. It is found that the integration of high-resolution DEM and high-resolution satellite images with GIS could be substituted for conventional aerial survey. In the present research, ArcGIS 8.2 (ESRI) is mainly used as a GIS analysis system for PC Windows.