These studies deal with the application of aerial photography as a source of both quantitative and qualitative 
information, to assist in the mapping of: 
1) urban land use, 
2) population, 
3) derelict (or spoiled) land. 
On the basis of nine broad land use categories, it was found that nearly ninety per cent of the urban land use 
be accurately identified from medium scale aerial photographs. 
Population densities of selected enumeration districts were determined with overall maximum errors of 
between one per cent and seven per cent according to the associated housing type. 
The extent of ‘spoiled’ land identified from the aerial photographs of the study area was over three times that 
recorded in the official Government statistics relating to ‘derelict’ land. 
8. Dubuisson, B. 
France 
CONTRIBUTION OF PHOTOGRAMMETRY TO 
AUTOMATED DATA PROCESSING 
After reviewing the resolutions taken at the Lausanne Congress in 1968, and the Delft Symposium in 1970, 
concerning the field of activity of Working Group IV-3, this paper makes some comments on the different 
projects included in this report. These projects are: 
- Coded Photogrammetric System for Automated Large-Scale Surveying and Property Locating Files 
with a Digital Topographic Cadastral Map for data banks, by B. Dubuisson 
: General Methodology of Automated Photogrammetric System, by Morris M. Thompson. 
- Advanced Photogrammetric Methods in Cadastre, including Stereo-Orthophoto Techniques, by Z. 
Jaksic 
- Mapping and Photointerpretation System Based on Stereo-Orthophotos, by T.J. Blachut. 
- Means and Methods in Automated Photogrammetry, a report from Sweden, by Sven G. Moller. 
This paper concludes by showing the importance of data processing in photgrammetry, because this provides 
basic data for making a general territorial analysis and socio-economic surveys. 
9. Ducher, G. 
France 
USING THE WILD B-8 STEREOMAT AT THE 
INSTITUT GEOGRAPHIQUE NATIONAL 
A succinct review 1s made of the experience acquired during four years of using the Wild B-8 Stereomat at 
IGN. Some operational precautions are described if good pictures are to be obtained. Breakdowns immobilized 
the camara for only about 10 to 20% of the time, but required an electronics laboratory to be set up 
on-the-spot. 
The results obviously depend on the nature of the ground and the quality of the initial picture, and they are 
especially satisfactory in an accidented region and on a medium or small scale. Automatic correlation is quite 
advantageous and makes excellent corrections even for very steep slopes. Planimetric accuracy is about 0.1 to 
0.2 mm, i.e. graphic accuracy. The altimetric plate of tangent dashes is often difficult to use and remains 
problematical for abrupt or superstructure-loaded reliefs. 
The Stereomat is a step toward automatic mapping, and its digital T.I. T.N. tape recorder makes various surveys 
on digitalized relief possible, as well as the recorded controlling of the automatic Matra-Sfom orthoprojector 
operating in a :3* chamber' mode under the control of a PDP8 computer. The extension of orthophotography 
can thus be expected in connection with the new possibilities becoming available in automatic mapping and 
needs of users. 
48