MEDEM10s are digital terrain elevation models of Maine, in grid format, based on USGS 7.5 minute DEMs (10 by 10 m square grid or data spacing). Digital Elevation Model (DEM) is the terminology adopted by USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of an array of elevations from ground positions at regularly spaced intervals, cast on a designated coordinate projection system, produced in 7.5 by 7.5 minute blocks from cartographic map contour overlays or scanned National Aerial Photography (NAPP) photographs. USGS DEM data are stored as profiles with a 10 or 30 meter square grid spacing in which the spacing of 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. USGS has used four methods to collect DEM data. Of these, only one, interpolation from vectors or digital line graph (DLG) hypsographic and hydrographic data, is currently used for 7.5 minute DEMs and other series. MEDEM10s, produced using 1:24000 cartographic map contour overlays, represent the 10 meter profile of USGS 7.5 minute DEM series. Elevation values are in meters.

MEDEM10s are digital terrain elevation models of Maine, in grid format, based on USGS 7.5 minute DEMs (10 by 10 m square grid or data spacing). Digital Elevation Model (DEM) is the terminology adopted by USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of an array of elevations from ground positions at regularly spaced intervals, cast on a designated coordinate projection system, produced in 7.5 by 7.5 minute blocks from cartographic map contour overlays or scanned National Aerial Photography (NAPP) photographs. USGS DEM data are stored as profiles with a 10 or 30 meter square grid spacing in which the spacing of 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. USGS has used four methods to collect DEM data. Of these, only one, interpolation from vectors or digital line graph (DLG) hypsographic and hydrographic data, is currently used for 7.5 minute DEMs and other series. MEDEM10s, produced using 1:24000 cartographic map contour overlays, represent the 10 meter profile of USGS 7.5 minute DEM series. Elevation values are in meters.