The main advantage lies in the flexibility of organizational structure with the possibility 
of decentralization of technical operations, If a three stage organization of the cadastral system 
is assumed as it is reasonable for countries with larger territories, the responsibilities for tech- 
nical operations may be distributed between a central office, several regional offices and a num- 
ber of local offices. (In smaller countries the responsibility for technical operations may be divi- 
ded between a central office and local offices). All these offices may be based on cooperation 
with private surveying companies and surveyors, In this configuration one can assume the follo- 
wing distribution of responsibilities, The central office may be responsible for control surveys, 
regulations, storage of data and their general exploitation, If the exploitation is based on the con- 
cept of data banks, that office would have to have large data processing facilities, To the regional 
offices may be given the responsability of execution of photographic flight missions, densificationof 
the control and production of stereo-orthophotos, The local offices, on the basis of stereo-ortho- 
photos provided by regional offices, would be responsible for the actual data acquisition, The 
inexpensive equipment for the exploitation of stereo-orthophotos (e.g. stereocompilers) may be 
relatively easily acquired and due to the simplicity of that equipment its maintenance should not 
cause any difficulties, The operating of the equipment does not require a high level of photogram- 
metric training, which is otherwise necessary in all other techniques, The reason for this is that 
all the complicated photogrammetric operations were already performed in the earlier stages 
during the production of the stereo-orthophotos, 
If one is concerned with a national information system as a superstructure of the cadas- 
tral system then the central or the regional offices would have the responsibility of supplying 
with stereo-orthophotos all the agencies responsible for establishment and maintenance of parti - 
cular information sub-systems, Here the advantage offered by the stereo-orthophotos is twofold : 
first, the acquisition of information would be executed in all instances on the same base and in 
the same reference system, Second, the collection of information would be performed by the 
experts from the particular technical or scientific discipline for which the particular information 
sub-system is being established, At this point one can better realize the importance of the fact 
that the three dimensional record with a multitude of information is retained in stereo-orthophotos, 
References 
Blachut, T.J., "Mapping and Photointerpretation System Based on Stereo-Orthophotos", NRC 
publication 12281, 1971, 
Blachut, T.J., ''Stereo-Orthophoto System', Bildmessung und Luftbildwesen, Vol, 39, 
25-28, 1971. 
Blachut, T,J, and M,C, van Wijk, "3-D Information from Orthophotos'', Photogrammetric 
Engineering Vol, XXXVI, 365-374, 1970. 
Dubuisson, B., "Intégration des Orthophotoplans dans la Photogrammétrie Cartographique', 
The Canadian Surveyor, Vol, XXII, No. 1, 135-144, 1968. 
Jaksic, Z., "Concepts in Photogrammetric Systems Design', Archives of Thirteenth Interna- 
tional Congress ofF.1.G., Commission 5, 507.3, 1971, 
Johansson, O,, ""Orthophoto Maps as a Basis for the Economic Map of Sweden on the Scale of 
1:10,000", The Canadian Surveyor, Vol, XXII, No. 1, 149-158, 1968. 
Radlinski, W.A., 'Orthophoto Maps vs.Conventional Maps", The Canadian Surveyor, 
Vol. XXII No, 1, 118-122, 19639. 
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