Digital roof model (DRM)using high resolution satellite image and its application for 3D mapping of city region

Abstract

In urban area artificial structures are built over crowdedly and show their complex three-dimensional (3D) characteristics. The authors create a concept of digital roof model (DRM) for giving a series of height of buildings roofs in urban area retrieved from a pair of high resolution images from satellites as IKONOS or QUICKBIRD. They develop consequently an automatic method to generate a DRM. Three-dimensional data of topography of the ground has been expressed mainly with the contour lines or the digital elevation model (DEM) obtained from aerial photographs so far. The contour lines or the DEM show the elevation of ground surface. In order to express correctly the detail of urban space structure, however, single data of ground elevation cannot be said enough. Thus the authors tried making an algorithm to obtain the roof elevation of buildings from high resolution satellite data. Two DRMs were generated for two urbanized areas concentrated with lower buildings and with taller buildings. The accuracy of the DRM was compared with the truth data. Differences between both heights of buildings by the truth and the DRM value became 5.2m rms. Fusing IKONOS spectral data and DRM product, a 3D bird's-eye view of the city region is presented. Though it shows a certain quality of reproducibility of the 3D structure, more improvement of DRM is required. Key word - Digital Roof Model (DRM), Bird's-eye view, High resolution9y Urban environment