DEM, or Digital Elevation Models, are a furthered look into the world of GIS. They are a sompletely digital terrain representation obtained by using a very high-tech system of cameras and remote sensing technology. It is technology that is so impactful, it has found itself in satellites and the Rover's Spirit and Oppurtunity sent to Mars.
Found - www.pasda.psu.edu
This blog is a map catalog in which I am displaying fifty different types of maps and a tid-bit of information that looks into the purpose of the map!