Global Topgraphy CD-ROMs Bill Sowerbutts Computer generated images of the Earth's surface relief can now be obtained fairly readily and have a multitude of uses in the earth sciences. The most obvious use is merely to show the three-dimensional shape of parts of the Earth's surface and in a way that is easier to visualise than traditional topographic maps and some other forms of presentation. Like traditional maps such images can be used as a backdrop to displays of your own spatial information or when you want to show some relationship between your data and surface relief.
Most earth scientists are now familiar with computer generated images and image processing software.
The difference between images of the Earth obtained by satellites, and those considered here is that the images of surface relief are generated by computer from topographic and bathymetric data that has been obtained by traditional means. They usually show oblique views of three-dimensional features whereas most satellite images present essentially vertical views of the Earth. Although the illustrations shown here are as grey-scale images, all can be produced in colour. Indeed, while there is little scope for changing the appearance of the grey-scale images, a wide variety of pictures can be produced by manipulating the same images when 256 colours are used. The easiest way to obtain pictures of the earth's surface relief is to use some of the pre-formed images now available.