HOWTO import SRTM elevation data

Background: Space Shuttle Radar Topography Mission

Download

• http://www2.jpl.nasa.gov/srtm/
• ftp://e0srp01u.ecs.nasa.gov/srtm/ New 2009: http://dds.cr.usgs.gov/srtm/

Import of original SRTM tiles in HGT format

Use the r.in.srtm module for automated import into a Latitude-Longitude location.

See:

• M.H. Bowman. Mapping freely available high resolution global elevation and vector data in GRASS. GRASS Newsletter, Vol.3, pp 7-10, June 2005. [ PDF ]

Import of CGIAR SRTM void-filled tiles

• SRTM 90 data in GeoTIFF format are available from http://srtm.csi.cgiar.org/. These come in 5 degree by 5 degree tiles. Horizontal resolution: 3 arc second (90 m at equator). Coverage: world. Import with r.in.gdal

Import of multiple SRTM tiles in one step

To simplify the import of multiple SRTM tiles, the tiles can be mosaicked first with gdalwarp:

Original SRTM tiles:

 # unzip all
 for i in *.hgt.zip ; do unzip  $i ; done
 # create mosaik (optionally reproject on the fly with -t_srs)
 gdalwarp *.hgt srtm_mosaik.tif
 # import
 r.in.gdal input=srtm_mosaik output=srtm_mosaik

CGIAR SRTM tiles:

 # create mosaik (optionally reproject on the fly with -t_srs)
 gdalwarp *.tif srtm_mosaik.tif
 # import
 r.in.gdal input=srtm_mosaik output=srtm_mosaik

Void filling of original SRTM tiles

The module r.fillnulls can be used. See screenshot

See:

• M. Neteler, 2005. SRTM and VMAP0 data in OGR and GRASS. GRASS Newsletter, Vol.3, pp 2-6, June 2005. [ PDF | Erratum 1/2006 (txt) ]

See also

• SRTM in Wikipedia