DTM - Digital Terrain Model

How to create a DTM?

There are two steps necessary for the creation of a DTM:

Collecting original x,y,z coordinates

You can collect altitude data of the earth’s surface from the following data sources:

• digitization of contour lines from topographic maps
• stereoscopic measurements from aerial photos
• stereoscopic measurements from (optical) satellite data (SPOT)
  - DEM of vegetation surface
  - gives already regular spaced data
• radar satellite data
  - gives already regular spaced data
• laser scanning measurements
• field measurements

Interpolation of a regular gridded DTM

The x,y,z coordinates collected from the above sources are usually irregular spaced. They have now to be transformed into regular spaced gridded data using different interpolation algorithms whereby "kriging" algorithms usually produce the best results. The chosen grid cell size depends mostly on the density of the collected irregular spaced data. The quality of the DTM is mainly determined by the density and accuracy of the collected original altitude data.

© 1999 TRIANET, Program of the European Union Socrates-Comenius
Last update on 05.05.1999 by Markus Zapke-Gründemann