DEM Construction from Contour Lines Based on Regional Optimum Control

Digital Elevation Model (DEM) data are widely used in many research areas such as Geographical Information System (GIS), hydrological analysis and soil erosion models. By minimizing the equations of HASM (High Accuracy Surface Modeling), subjected to equality constraints from discretizing vector contour lines and to boundary constraints from regional points between contour lines, a method called HASMROC(Regional Optimum Control) for constructing DEM from contour lines is presented. A case study is given on converting Gauss synthesis surface´s contour lines into DEM and the derived contour lines from simulated DEM is compared with the original ones. Information contained in between original contour lines can be most used by HASMROC, while it cannot be used by HASM and by the other DEM construction methods, so HASMROC can produce a more reliable result from contour lines. Much more kinds of original data sources and data sources of different qualities can be handled by HASMROC method in the future through regional optimum control.