Brandt, Steffen 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Figure 1. Elevation levels from the DTM and two-dimensional watercourse network 
(DTM elevation levels from green (approx. 50 m NN) through yellow to red (approx. 100 m NN)) 
3 DIGITAL TERRAIN MODEL 
3.1 Automatic DTM Generation using MATCH-T as an Example 
The digital terrain model applied in these environmental compatibility studies can cover an area of over 100 knf,, and is 
crucial for the investigation of water as a protected resource. Due to the necessity of up-to-date, accurate information, as 
well as cost-effectiveness, aerophotogrammetry (usually a scale of 1:6000) is the only feasible method of recording a 
large part of the data required by DSK. Digital photogrammetry is being increasingly applied by DSK-DG to achieve 
equally accurate results in certain areas. 
In the Department of Geoinformation Services, due to the high standards required (assessors, water boards), a two-stage 
procedure was agreed upon for the measurement of the digital terrain model. F irstly, the DTM stage 1 was 
  
214 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.