GTOPO is a global digital elevation model. Elevations in GTOPO are regularly spaced at 30-arc seconds (approximately 1 kilometer) for the Earth's land surface. There are 120 pixels per degree. This 2.6 gigabyte data base comes on 3 CDROMs.

The data base comes with a program called TOPOtoIMAGE that will translate GTOPO30 into Geocart Image data bases.

The program allows you to color the GTOPO30 data bases with one of over a thirty pre set "gradients" or create your own.

The price of the GTOPO30 data base and the TOPOtoIMAGE program is $750