中文摘要：

针对构建的不规则三角网，依据相邻三角形法线向量之间的夹角为判断依据，给出一种基于平面不规则三角网（TIN）的DEM数据压缩方法。在详细推导了压缩准则的基础上，给出了压缩判断阈值的确定方法。为了说明该压缩方法能顾及地形特征，对压缩方法的可靠性作详细介绍，并说明了该方法的可行性。

英文摘要：

A new method of data compression of Digital Elevation Model （ DEM ） which is based on the Triangle Irregular Network （TIN） is presented in this paper. In the method, the angle between triangle normal vectors is used as the measure for identifging points which should be removed, in which way the original DEM data can be compressed while the data storage space is reduced and the successive disposal speed will increase under the precondition of minimizing the loss of model precision. Furthermore, the reliability of the data compression method is analyzed to show the feasibility of the method.