关键词: SRTM, 等高线, 空值区域, 内插

Abstract:

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 1: 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.

Key words: contour, interpolation, SRTM, voids