Improved SRTM Digital Elevation Data

February 20, 2012

GeoNames is switching from the original SRTM data provided by NASA to the processed srtm v4.1 data provided by cgiar. The extract files now contain srtm data where available and gtopo30 elsewhere.

SRTM is digital elevation model from 56° S to 60° N in a three arcsecond (90 m) resolution. The original data provided by NASA contains small holes of no data over water bodies, mountainous regions and desertic regions. Andy Jarvis and Edward Guevara of the CIAT Agroecosystems Resilience project (CGIAR), Hannes Isaak Reuter (JRC-IES-LMNH) and Andy Nelson (JRC-IES-GEM) have further processed the original DEMs to fill in these no-data voids. This involved the production of vector contours and points, and the re-interpolation of these derived contours back into a raster DEM.  The Consultative Group on International Agricultural Research (CGIAR) is a global partnership that unites organizations engaged in research for sustainable development to reduce poverty and hunger, improve human health and nutrition, and enhance ecosystem resilience.

GeoNames has been kindly granted permission to use the processed srtm data. In exchange CGIAR has been given complimentary access to the premium web services. Thanks to Andy Jarvis and all the others involved.

srtm3 elevation for N46 E8 in the Swiss Alps - void areas in red

srtm3 v4.1 N46 E8 in the Swiss Alps - no data voids filled by cgiar

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2 Responses to “Improved SRTM Digital Elevation Data”

  1. Bill Mackintosh Says:

    This is not a comment on your post of 2/20/2012, but a suggestion for a minor correction to a geonames readme text file that I see no way to modify through your wiki and do not know where to post the suggestion.
    My browser shows the source of the file as: http://download.geonames.org/export/dump/readme.txt
    The file states, in part, “…please do use the wiki-style edit interface on our website
    http://www.geonames.org to correct inaccuacies and to add new records.”
    The word inaccuracies is misspelled (humorously!) as “inaccuacies” but would be easy to correct for those with access.
    Thank you for your help.


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