一种面向DEM多尺度表达的傅里叶能量谱模型

A Fourier Energy Spectrum Model for DEM Multi-scale Representation

针对数字高程模型(digital elevation model,DEM)数据的多尺度表达问题,根据DEM格网数据在能量谱密度中“低频-高能-大尺度”的对应关系,在化简中关联地形语义特征,构建了DEM数据的多尺度表达模型。实验结果表明,该模型可以实时动态派生不同尺度下的DEM数据,通过等高线放样观察发现,该模型派生的DEM数据满足地形表达、空间认知和制图综合中的“保留主要地形特征、舍弃次要地形特征”的基本原则。与常用的DEM化简方法进行高程值统计以及坡形变化的定量对比分析,结果表明该方法在统计意义与结构意义上都具有较好的效果。

Objectives:The accurate and fast multi-scale representation of digital elevation model(DEM)is the key basis for its multi-scale application.We aim to propose an automated and high-quality multi-scale representation method for DEM.Methods:We construct a model of DEM data for multi-scale representation,according to the corresponding relationship of“low-frequency-high-energy-large scale”in energy spectral density,and relate topographic semantic features in simplification.Results:The result shows that this model can dynamically derive DEM data at different scales.The figure of contour lines derived from this model can meet the basic principle of“retaining main topographic features and abandoning secondary topographic features”in topographic expression,spatial cognition and cartographic generalization.Quantificationally compared with traditional DEM simplification methods in elevation and slope shape,this method shows similar or better effect in statistical and structural significance.Conclusions:The model based on the Fourier energy spectrum can effectively express DEM data with different scale requirements.