Digital Elevation Model (DEM), Digital Terrain Model (DTM), DEM Maps

By: AeroMetric  09-12-2011
Keywords: Topographic Information

A Digital Elevation Model (DEM) is a collection of discrete elevation points at regularly spaced intervals. The model reflects abrupt changes in relief such as incised streams, ridge lines, and slope breaks.

The Two Methods to Obtaining a DEM

1. Direct extraction of topographic information using well established photogrammetric techniques. This method has evolved from manual interactive collection of breaklines and mass points to a fully automated method, using image matching techniques.

2. Using laser and radar-based sensors to automatically derive elevation information.

Regardless of the method used, the recorded data is post-processed to generate the final DEM.

Keywords: Topographic Information

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