Digital Terrain Models are being used for planning and hydrological applications,
but also for visualization and many other tasks. For all applications, it is necessary
to know the model quality, because it has an impact on the quality of the decisions
that are drawn from the terrain model applications. In this paper we present a
method that is suitable for comparing two terrain models to each other. Vertical, but
also horizontal displacement of terrain features can be found automatically, which
are systematic errors and are in the main focus of this paper. However, random
errors can be quantified, too. This method allows establishing a vector field of
differences between two models, measuring the deviation from one to the other.
These deviations are a measure of quality of one model against the other. Emphasis
will be put on comparing terrain model from NASAs Shuttle Radar Topographic
Mission to terrain models of known quality in Brazil
