Abstract:
The state bureau of surveying mapping of China has planned to speed up its development of spatial data infrastructure (SDI) in the coming few years. This SDI consists of four types of digital products, i.e., digital orthophoto, digital elevation models, digital line graphs and digital raster graphs. For the DEM, a scheme for the database building and updating of 1:10 000 digital elevation models has been proposed and some experimental tests have also been accomplished. This paper describes the theoretical and/or technical background and reports some of the experimental results to support the scheme. Various aspects of the scheme are discussed such as accuracy, data sources, data sampling, spatial resolution, terrain modeling, data organization, etc.