Basic HTML version of Foils prepared November 29 98
Foil 12 Digital Elevation Models
From 3D Geographical Information Systems in Tango CEWES Tango Training -- November 17-18 98. byRemek Trzaska, Pawel Roman, Chris Walczak, Marek Podgorny
A DEM consists of a sampled array of elevations for a number of ground positions that are normally at regularly spaced intervals. These intervals determine the spatial resolution of the DEM.
The USGS offers DEM in Public Domain having a spatial resolution of 90 m whereas commercial organizations have the DEM's at 30 m.