Processing Terrain Data

Data Set Coverage Resolution Level Format Type Web Link
ASTER Global 1 arc-second (~30m)
1° by 1° tiles
GeoTIFF https://earthexplorer.usgs.gov/
CDED Canada 0.75 arc-second (~23m)
3 arc-second (~100m)
DEM http://www.geobase.ca/
GTOPO30 Global 30 arc-second (~1 km)
30 arc-second (~1 km)
DEM https://earthexplorer.usgs.gov/
GMTED2010 Global 15 arc-second (~500 m)
7.5 arc-second (~250 m)
GeoTIFF https://earthexplorer.usgs.gov/
IFSAR Alaska 2 arc-second (Alaska)
1 arc-second (U.S., most of Canada,
Mexico, Hawaii, portions of Alaska)
ArcGrid https://earthexplorer.usgs.gov/
NED 3 U.S. 1/3 arc-second (U.S.,
Hawaii, and portions of Alaska),
or 1/9 arc-second (limited areas  of U.S.)
GridFloat / IMG http://nationalmap.gov/viewer.html
SRTM 1 U.S. SRTM1: 1 arc second (~30m) SRTM https://earthexplorer.usgs.gov/
SRTM 3 Global SRTM3: 3 arc-second (~100m) SRTM  
SRTM30 Global SRTM30: 30 arc-second (~1 km) SRTM http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/