GTOPO30 is a global digital elevation model (DEM)
resulting from a collaborative effort led by the staff at the
U.S. Geological Survey's EROS Data Center in Sioux Falls, South
Dakota. The name GTOPO30 is derived from the fact that
elevations in GTOPO30 are regularly spaced at 30-arc seconds
(approximately 1 kilometer). GTOPO30 was developed to meet
the needs of the geospatial data user community for regional and
continental scale topographic data. This release represents the
completion of global coverage of 30-arc second elevation data
that have been available from the EROS Data Center beginning in
1993. Several areas have been updated and the entire global
data set has been repackaged, so these data supersede the
previously released continental data sets.