Global 30-Arc-Second Elevation Data Set

Project Description
Global 30 Arc-Second Elevation Data Set (GTOPO30) is a global
raster Digital Elevation Model (DEM) with a horizontal grid
spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30
was derived from a variety of raster and vector sources. The
data is expressed in geographic coordinates (latitude/longitude)
and is referenced to the World Geodetic Survey (WGS) system of
1984 (WGS84). The files are available in generic binary (16-bit
signed integer) format and are distributed on CD-ROM, FTP
(compressed), and 8-mm tape.

Prices:
CD-ROM บ.00 per CD
8-mm tape (high density) ฟ.00
FTP download no charge

For more information, link to
http://edc.usgs.gov/products/elevation/gtopo30.html#description