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GRASS Help System |
A great amount of information is stored on paper maps. This information can be much more easily manipulated in a computer database. To get map data into a GRASS database, map data (analog data) can be converted into digital data by tracing relevant map features using a digitizer. The digitizer converts map data into a GRASS vector format.
Frequently, map data cannot readily be digitized directly from original paper source maps. Paper maps will generally contain many types of information. The person that is digitizing must know exactly what information is to be digitized. It is therefore generally necessary for the user to prepare a map(s) containing only the information that is to be digitized before beginning to digitize.
Have the following items before beginning to digitize:
"Cartographic Issues in the Development of a Digital GRASS Database" (Ruiz and Messersmith, 1991) describes how maps should be prepared for digitizing; it should be read prior to digitizing.