READHGT: Import/download NASA SRTM data files (.HGT)

Imports or download SRTM worldwide digital elevation model data files.

This function imports .HGT "height" binary data files from NASA SRTM global digital elevation model of Earth land, corresponding to 1x1 degree tiles of 3-arc seconds resolution (SRTM3, around 90 m) and 1-arc second (SRTM1, around 30 m), and returns coordinates vectors latitude and longitude, and a matrix of elevation values.

The function includes also an automatic download of data from the USGS SRTM webserver, so indicating latitude and longitude is sufficient to get the data and instant map plot anywhere in the World.

Few examples:

readhgt(46:47,-123:-122)

plots a map of Seattle and surrounding volcanoes,

X = readhgt(48,2,'plot');

plots a map of Paris (France) and returns downloaded SRTM data in structure X.

Type "doc readhgt" for syntax, options, other examples and use.