中国区域SRTM90m数字高程数据空值区域的填补方法比较

Comparison of Patching Methods of SRTM 90m DEM Voids in China

本文对中国地区SRTM90m分辨率的数字高程数据的空值区域做了提取和分析,在此基础上尝试了4种内插填补的方法。并对各种处理方法的过程及结果做了比较,从而确定先从SRTM90m数据中直接提取等高线．再内插生成DEM,用内插出来的值填补原始数据的方法在目前较为适用。此外本文还提出了一些后期处理方法以完善数据。

SRTM90m digital elevation data contains no-data voids. Based on the analysis after retrieving the voids in the region of China, several processing methods are used to fill in them. Those methods are： （1） patching the void area with DEM data interpolated from contour line from paper map at scale of 1：1 000 000; （2） adding contour line from paper map at scale of l： 1 000 000 to the void at SRTM90m data and then interpolating the patched data,; （3） patching the void by directly interpolating SRTM90m, and （4） retrieving and interpolating contour line from SRTM90m data. It is verified that the most operable method to fill in no data area is to interpolate the contour line which is retrieved directly from the original SRTM90m, but this method is effect to patch the small no data area; when no data area is big, it is better to use contour line from paper map with large scale, however, the quality of current paper map with large scale is not high enough, furthermore, the acquisition and publishing contour line from paper map with large scale （e.g. large than 1：1 000 000） is limited by related state security regulations. Further processing steps such as to add water body region are provided for better application of the data.