PROKDR.-ING. KLAUS LINKWITZ 
TECHNISCHE HOCHSCHULE STUTTGART 
INSTITUT FÜR ANWENDUNGEN DER GEODÄSIE 
IM BAUWESEN UND LEHRSTUHL ill FÜR GEODÄSIE 
REPORT ON THE DIGITAL TERRAIN MODEL STUTTGART 
Prof. Dr.-Ing Klaus Linkwitz, Stuttgart 
1. Theoretical Elements of the DTM 
As any DTM may be defined as the analytical numerical descrip 
tion of an irregular surface, based on the measurement of dis 
crete points of this surface, characteristics of a special DTM 
can be characterized under three different aspects. 
a) Method of registration 
The discrete points necessary to establish the DTM may be se 
lected in different ways: at random, along characteristic lines, 
etc. Being of the opinion that the irregular shape of topography 
calls for registration of topographically significant lines and 
points in the Stuttgart DTM registration follows characteristic 
lines of the terrain: contours, lines of maximum decline, lines 
of changes in slope. This continuous model can be registered 
simultaneously with ordinary photogrammetric map production. 
b) Method of mathematical representation 
Surface elements of the DTM may be approximated by linear or 
nonlinear interpolation. Since registration follows already 
characteristic lines, here linear interpolation has been adopted 
so far. Investigations for non-linear interpolations are being 
carried out. 
c) Data to be calculated from the DTM 
For any given pair of ground coordinates x^, y^ the DTM should 
yield the corresponding height z^. Heights should also be cal 
culated along sections within prescribed intervals. This is pos 
sible with the model demonstrated as well as the automatic draw 
ing of arbitrary cross-sections. 
Reference: 
BILDMESSUNG UND LUFTBILDWESEN 
Sonderdruck, 35. Jahrgang 1967 
"Ein kontinuierliches digitales Modell, dargestellt 
am Beispiel des Deutschen Pavilions Montreal" 
von K Linkwitz, Stuttgart