Major DEM Sources

Digital elevation data can now be obtained for any place on the Earth, at several resolutions. This document will discuss the major sources for reliable and freely available DEM data.  In order to choose the right source for DEM data, there are two main criteria to consider: geographical region of interest and spatial resolution. Below is a table that summarizes the DEM data sources that should be of interest to you.

Source Type

Geographical Region

Spatial Resolution


Source Link

National Elevation Dataset (NED)

U.S., Puerto Rico, Territorial Islands of the U.S., and Mexico

1 arc-second (30 m)

1/3 arc-second (10 m)

1/9 arc-second (3 m)

2-arc-second (60 m) – only Alaska

Most preferred for continental U.S.

The National Map Viewer

Shuttle Radar Topography Mission (SRTM)




3 arc-second (90 m)

1 arc-second global

1 arc-second for U.S.

Version 2: finished

Version 3: Void fill

Version 3

USGS Earth Explorer

Earth Explorer

Reverb | Echo
for Version 3

ASTER Global Elevation Data


1 arc-second (30 m)

Only between 83ºN and 83 ºS

USGS Earth Explorer

Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010)


30 arc-second (1 km)

15 arc-second (450 m)

7.5 arc-second (225 m)

Replaced GTOPO30, preferred for working with very large regions

USGS Earth Explorer