THE APPLICATION OF PHOTOGRAMMETRY AND SURFACE 
MODELLING IN COMPUTER-AIDED CHANNEL DESIGN 
v Gabor Remetey-Fülópp 
Institute for Hydraulic Planning, Budapest 
Introduction 
The computational photogrammetry as advanced 
Surface data acquisition procedure combined 
with use of integrated engineering program 
packages and optimization techniques has in- 
creased the efficiency of the design techno- 
logy especially in road projects, This paper 
is intent to demonstrate, how these aids can 
apply in open-channel hydraulics, where the 
digitized photogrammetric measurements are 
first transformed into the ground system a- 
nalytical way, then processed by specific 
problem-oriented engineering programs, 
  
Figol Selected test area /upper part/ 
41 
Location of the test area 
For selection, topographic maps at scale 
1/25000 and 1/10000 were usede About the 
chosen test site, a channel to be rebuilt, 
aerial photographs 1/4800 scale were avail=- 
able /Fig. 1,2/. In order to classify featu- 
res first by visual interpretation within 
the delimited area of interest, contact co- 
pies of stereo pairs were analysed with ste- 
reoscopic viewer, The relative significant 
differences in elevation /about lo metres/ 
and the fact that the selected area was o- 
verlapped by more models securing an environ- 
ment which is near to the common engineering 
practice and is suitable for analysis on sur- 
face modelling. We have chosen well identifi- 
able features for bridge and baseline points, 
Marked using point transfer device, the base- 
line - presigned in the practice - served as 
references for the geometric positioning rou- 
tines of the available Integrated Civil Engi- 
neering System developed by the MoIoTe [9]. 
The boundaries of the band of interest were 
also marked both on the diapositives and paper 
prints. 
  
Fig.2 Selected test area /lower part/ 
Photogrammetric strip formation 
After due considerations taking into account 
Specific circumstances as operational effici- 
ency and on-line plotting possibility, we de- 
cided to carry out the photogrammetric measu- 
rements on the first order Wild A-1o stereo- 
raph at the Delft University of Technology 
PTHD/ . For the strip adjustment of the three 
photogrammetric models the method of indepen- 
dent model triangulation /IMT/ was used, The 
sufficient number of control points were ava- 
ilable for the test &rea, have made it possib- 
le to employ 2-2 horizontal and vertical cont- 
rols at both ends of & bridging interval /fig. 
3/. For determination of the projective centers