利用地形信息强度进行DEM地形简化研究

Research on Terrain Simplification Using Terrain Significance Information Index from Digital Elevation Models

在对现有的DEM地形简化方法进行总结分析的基础上,提出了一种利用地形信息强度指数的DEM简化方案。首先提取DEM点位地形信息强度指数值,然后通过阈值法确定候选地形特征点重构DEM,以国家基本比例尺1∶5万DEM作为参照目标,并将重要点法和三维道格拉斯法作为对比方法,对应用该方法进行地形简化的效果进行了综合评价。实验结果表明,该方法应用于大范围DEM简化中可以有效地保留地形骨架的结构特征,同时具有较高的数值精度,可以满足不同层次的多尺度DEM建模的要求。

We present a new method for simplifying terrain using terrain significance information （TSI） index from DEMs. Firstly, TSI index of each grid cell based on DEMs is extracted. Secondly, critical elevation points are extracted from original DEMs for constructing target DEMs with proper TSI index threshold values. Finally, 1 ： 50 000 DEMs taking as reference target, and very important points （VIP） and three-Douglas-Peucker （3DD-P） being as verify methods, the terrain simplification effect of the DEMs reconstructed with the method is analyzed and evaluated. The results show that the terrain simplification method based on TSI index is not only with better numerical precision, but also effective in reducing the terrain distortion by keeping terrain skeletons to meet the demands in different levels of multi-scale terrain digital modeling.