The speaker hoped that such a general set of programmes could be supplied. The problem, however, is rather 
the co-operation of individual organizations in applying cost and accuracy model data which is required as 
input. 
The Chairman remarked that, although the two speakers have analysed the problems, and have offered some 
suggestions for research, they have not supplied any practical solutions to the problem. Therefore, a lot of work 
has still to be done in the field of planning, and this should preferably be formulated in a Resolution for the 
next Congress. The Chairman requested the co-operation of the audience in formulating a proposal to this 
effect, and delivering this to a member of the Resolutions Committee. He then closed the session. 
Wednesday July 26 1972, 10:45 
Chairman: C.O. Ternryd 
D.T.M. and presented papers Session 
Three Invited Papers were presented: 
C.O. Ternryd: Report of W.G. IV/1: “Photogrammetry in Highway Design”. 
M.H. MacLeod: ‘“Semi-Automated Large Scale Mapping”. 
W. Blaschke: ‘Application of Orthophotomaps in Highway Work” 
A paper by E. Benner and R. Schult entitled “Report on a Digital Terrain Model"' was presented by K. 
Linkwitz. He outlined the development of the IAGB-DTM system. To reduce storage space and processing 
time, the system is based on a rectangular arrangement of points, such that only the heights of terrain points 
have to be stored. Terrain data in the form of digitized contours or irregular grids have thus to be first 
transformed to this regular pattern. 
A second paper, by T. Maruyasu and S. Murai, “Topographic Information Processing System and its 
Application to Civil Engineering" describes the Japanese DTM system. Although developed as a strip system 
for the computation of earthwork quantities in highway design, it is at present being more profitably employed 
in urban development and construction projects. 
Two other presented papers were announced: 
S.E. Masry: Highway Applications of the Analytical Plotter"' 
H. Nakamura: **A digital terrain model from analytically presented contour lines". 
M. Sautreau presented a paper, “Numerical Cadastral Surveying Test by Analytic Photogrammetry ", which 
described a cadastral surveying test to compare ground and photogrammetric methods. The latter was executed 
at three scales of photography, namely 1:8000, 1:5000 and 1:2500. The main conclusion of the experiment was 
that the results at the most economical photo scale, 1:8000, were not within French cadastral tolerances. 
In discussion, the speaker confirmed that ground distances were measured by tapes, and admitted that this 
could have caused errors in distances of over 100 metres. This might partly explain the rather poor results. 
After announcing one other presented paper, ‘“ Aerophotogrammetry Applied to the Problem of Land Holding 
and Potential Use of Land in the Mexican Republic", by R.B. Equiarte and J.J. Carbonnell, the President 
remarked that previous Congresses had seen a large number of papers, particularly on accuracies of cadastral 
applications. However, since there are far more problems involved in the legal and administrative aspects, he 
intended to draft a Resolution proposing that this topic be dealt with. The audience was invited to put forward 
suggestions in this respect, and the session was closed. 
Friday July 28 1972 10:45 
DTM Discussion Session 
A brief review was given of the development of the DTM over the past 20 years, initially intended as an aid 
in the selection of alternate routes during the preliminary design phase. Although a large number of systems 
are available at present, only a few of these are used in practice, and then only in the final design phase. A 
possible reason for this is the fact that programmes are not yet available to perform operations such as 
automatic route selection, etc.