7METI/ERSDAC, NASA/LPDAAC, USGS/EROS. ASTER Glob- al DEM validaiton summary report[R].2009.
8Reuter H, Nelson A, Jarvis A, 2007. An evaluation of void-filling interpolation methods for SRTM data[J]. International Journal of Geographical Information Science, 21 (9): 983-1008.