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GRASS Help System |
Increasingly, geographically-referenced spatial data are being made available in digital format. In order to use these data within GRASS, the user must be able to extract data from their magnetic storage media, import them to GRASS data format, and spatially reference them with other existing digital data. The section, "Sources of Digital Data" lists some available digital data sources for GRASS data sets.
Other sections (see "Extracting Digital Elevation Data" and "Extracting Digital Imagery Data") discuss the extraction of elevation and imagery data from magnetic tape. Specific procedures for extracting these data from tape and importing them into a GRASS data base are described in the papers "DTED and DEM Elevation Data Extraction" and the "GRASS Imagery Tutorial".
GRASS commands also exist to perform generic tape data extraction and manipulation. Those commands are listed below.
For more information on a specific command, select a command and press ESC.
Also, see the section, "UNIX: dd, tar" for information on ways in which UNIX programs can be used to extract data from tape.