The new three-dimensional map of Earth has been completed. Mountain peaks and valley floors across the globe can now be seen with an accuracy of just one metre.
A digital elevation model (DEM) is a digital file consisting of terrain elevations for ground positions at regularly spaced horizontal intervals. The USGS produces five different digital elevation products. 1-Degree DEMs correspond to the 3 arc-second – 3- x 3-arc-second data spacing – (or 1:250,000-scale) USGS topographic map series, and are available for all of the […]