Constructing A Quality DEM Base On The Contour Lines Data

With the development of Geographic Information System, Digital Elevation Model plays more and more of important role. DEM is not only as a basic data, but also as a method of thinking.This Paper discusses the theories and methods on making high quality DEM bases on terrain feature from digital contour line. Here the paper builds the model with the method that build Triangulated Irregular Network form contour line. Introduce and compare some common method to build TIN; And then study and experiment on distilling terrain line by using Delaunay triangulated network ; In order to improving modeling efficiency and model fidelity, paper studies the modeling methods and improving measure on constructing TIN considering limitation of terrain character. Then paper introduces arithmetic from TIN to Regular Square Grid DEM, provides an efficient algorithm for converting TIN to GRID base on the spatial index. Finally, the paper assesses the precision of the DEM data.At last, the paper summarizes research productions and development direction.