50 
REVIEW OF THE PRESENT STATUS OF THE APPLICATION OF THE DIGITAL 
TERRAIN MODEL AND THE SEMIAUTOMATED PHOTOGRAMMETRIC TECHNIQUE 
TO HIGHWAY AND RAILWAY DESIGN AND THE TREND OF FURTHER DEVELOP- 
MENT 
  
  
  
Contribution by Karl Kraus, 
Vienna Technical University. 
The report of ‘a university teacher on the theme set is inevi- 
tably keyed rather to research and development than to practical 
experience. This contribution is limited to the following two 
items. 
- Digital terrain model (DTM) and digital contouring. 
- Digitally controlled orthophoto production. 
1.  DTM AND DIGITAL CONTOURING 
At the ISP-Congress at Ottawa, in 1972, the Stuttgart Contour 
Program (SCOP) was presented /3/ /9/. By means of linear least 
squares interpolation and filtering of terrain points arranged 
by profiles and at random (x, y, z-coordinates), SCOP computes 
the neights of a regular grid. The heights of this grid consti- 
tute the Digital Height Model (DHM). 
In the second part of SCOP the intersecting points of the con- 
tour lines are interpolated linearly with the grip lines of the 
DHM. The series of points sorted along the contour lines are 
output on magnetic tape and mapped off-line by an automatic plot- 
ter. 
1.1 Application 
In January 1975 W STANGER, Institute of Photogrammetry, Stuttgart 
University, reported on the results yielded in the meantime by 
the program. He has produced 25 contour line maps on scales of 
1:500 (contour line interval 0,5 m) to 1:24 000 (contour line in- 
terval 40 ft.). The initial data were partly recorded photogram- 
metrically and partly terrestrially. Tne computing times per map 
on the CDC 6600 are between 90 SS (350 terrain points) and 1090 SS 
(16 500 terrain points). 
In cooperation with Prof ENGEL, Institute of Railway and Trans- 
port Economy, Vienna Technical University, SCOP was applied to a 
traffic-economical analysis. The initial data were the costs that 
a road user on an average is obliged to incur daily to meet his 
vocational and private requirements. These costs were determined 
at about 500 points within the area of Vienna and elaborated with 
the aid of SCOP in the form of lines of equal costs to give a 
graphic representation. In the meantime relative to several cost 
  
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