Center for Spatial Analysis Technologies
| Description
Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a regular array of elevations cast on a designated coordinate projection system. The DEM data are stored as a series of profiles in which the spacing of the elevations along and between each profile is in regular whole number intervals. The normal orientation of data is by columns and rows. Each column contains a series of elevations ordered from south to north with the order of the columns from west to east. Fourteen 1-degree DEM (3- by 3-arc second data spacing) provides coverage in 1- by 1-degree blocks. The data are paneled together and clipped to the boundary of the State of Georgia. Data are posted every 3-arc seconds (60-90 meters). Slope is a direct derivative of the DEM, with the documentation information for the DEM applying directly. |
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