GTOPO30
GTOPO30 is a digital terrain model from the United States Geological Survey ( USGS ).
It is freely available and can be downloaded from the Internet . With a ground resolution - that is the distance between the individual elevation information of the terrain - of 30 arc seconds (about 1 km) it is the best freely available digital terrain model for the entire surface of the earth . The newer, more finely resolved SRTM data , on the other hand, are only available from a limited part (approx. 80%) of the earth's surface.
The data can be displayed with the Kashmir 3D software (see web link).