中文摘要：

免费公开的SRTM DEM数据用图广泛,但存在大量的空洞。针对SRTM DEM空白处填补现状,利用MATLAB编程特性,编写线性插值、三次插值、最邻近插值的MATLAB代码,选择湖南西部丘陵山地进行空白填补实验。通过对比分析其最大值、最小值、标准差、中误差,得出三次插值法填补的效果最佳,生产的等高线最光滑。该方法与结论能为类似地区DEM插补方法选择提供参考。

英文摘要：

SRTM DEM,which is free to the public,contains a lot of blank cells.This paper introduced the characteristics of SRTM DEM data and the research status of the voids filling at present.Taking advantage of object oriented programming features of MATLAB,we wrote codes which contain the calculation methods of linear interpolation,third order polynomial interpolation,nearest neighbor interpolation to fill SRTM DEM blank cells for Hunan west hills,and made comparative analysis of the processing results of three methods.We found that the third order polynomial interpolation method works best and produces the most smooth contours,which offers a new reference in selection of interpolation method of SRTM DEM for similar DEM areas.