下载DEM数据，发现主要有两种：SRTM和ASTER
ASTER GDEM is considered a more accurate representation than the SRTM elevation model in rugged mountainous terrain. But you should really take a look for yourself.
对比看好像ASTER要好点？
网址：https://earthdata.nasa.gov/
选这个：
进来之后搜索：
然后选择地区直接下载即可：
