Image over
SRTM Elevation by
NASA, showing the
Cape Peninsula and
Cape of Good Hope,
South Africa in the foreground. GIS or
geographic information system is a computer system that allows for visualizing, manipulating, capturing, and storage of data with associated attributes. GIS offers better understanding of patterns and relationships of the landscape at different scales. Tools inside the GIS allow for manipulation of data for spatial analysis or cartography. , normalized as 8-bit grayscale, where lighter values indicate higher elevation. A
topographical map is the main type of
map used to depict elevation, often through
contour lines. In a
Geographic Information System (GIS),
digital elevation models (DEM) are commonly used to represent the surface (topography) of a place, through a
raster (grid) dataset of elevations.
Digital terrain models are another way to represent terrain in GIS. USGS (United States Geologic Survey) is developing a 3D Elevation Program (3DEP) to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States, Hawaii, and the U.S. territories. There are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3, 1, and 2 arcseconds. ==See also==