A Simplified Approach to DEM Based on Important Points and the Triangular Irregular Network Angles

A digital elevation model (DEM) is a digital representation of terrain. With the extension of the range and increase in resolution, there are a number of problems with the high-density elevation data contained in the digital elevation model. For example, data redundancy and huge amount of data, etc., which can cause inconvenience in subsequent storage, processing and applications. It is therefore necessary to simplify the DEM to varying degrees, depending on the needs. In this paper, a DEM simplification method based on important points and the triangular irregular network (TIN) angle was proposed. Firstly, the DEM was simplified by extracting important points from regular grid model. Subsequently, the TIN is created by the important points. A secondary simplification of the TIN was performed based on the angle between adjacent triangles to obtain the final simplified result. The experimental results demonstrated that the algorithm can effectively reduce the data redundancy of the DEM while ensuring the accuracy of the terrain. At the same time, the original features of the terrain were well maintained and good visualization was retained.