r.in.srtm imports SRTM HGT files into GRASS.
SRTM Version 1 and improved Version 2 data sets can be downloaded from
NASA at this site: http://dds.cr.usgs.gov/srtm/
SRTM tiles are of 1 degree by 1 degree size. The SRTM filename contains the
coordinates which refer to the center of the lower left pixel (e.g., N51E010:
lower left cell center at 10E, 51N). To identify a tile name, a grid can be easily
visualized by d.grid: