How to get DEM data

There are more than seven ways to obtain DEM data, namely: ground survey, photogrammetry, stereo remote sensing, GPS, topographic map hand tracking digitization, topographic map screen digitization, laser scanning, interferometric radar and so on.

Specific as shown in the figure:

Extended introduction:

Free access to 30m DEM data (reference source: Baidu Library):/link? URL = c-expk 7 e 09 NZ vcx-8 nkq 8 frmg 9 enxdoitsmngari 1 E8 z 6 fbtzfwt 6 smnsyejsrvbn 7 hbrhxrwiwwmr 2 iqtq 1 JK 4 xx 9 ljwgjy-6 zrwyudo