Digital Geography

8. January 2015

SRTM-1 (1 Arc second) now available with large global coverage

With this post I would like to come back on a topic from September 2014. In this blog post on Digital-Geography I announced that from September 2014 until September 2015 high-resultion SRTM-data will be provided for free by the USGS. We also announced the estimated release dates for certain regions around the globe.


SRTM-logo (Source:


After checking the progress of the release in EarthExplorer, I realized that the release is proceeding much faster than expected. Till this day, only Norhteast Africa is missing. Parts of Canada, Russia, Greenland, Scandinavia, Artica and Antarctica are missing due to the SRTM coverage limit of the mission (56°S-60°N).

Global coverage of SRTM-1 and Gap in Northeast Africa


Before September 2014, only the USA was provided with the higher resoluted SRTM-1 images with a resolution of approx. 25m. All other regions only had the chance to use the SRTM-3 with 90m ground resolution.

From now on, SRTM-1 can beat the free ASTER-DGM with a large global coverage. It’s worthy to give it a try. Have fun in examining the new data for your region!

Principle of SRTM (Source: