Digital Elevation Data

The term "DEM" (Digital Elevation Model) can refer either to a specific elevation file format, or to gridded elevation data in general.  Some people use "DTM" (Digital Terrain Model) as the more general term.

File Formats

Global Elevation Datasets (SRTM, GTOPO30, GLOBE..)

Caves, Overhangs, Non-heightfield Elevation

Regular Grid Quality Issues

Interpolation and Sampling

Compressing Elevation Data

Cell Registration