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Ultimately this last concept of a global information system can combine the advan-
tages of all aforementioned system types. if it is possible to establish such a system.
3. Obstacles to Data Integration
While an integrated information system is generally considered as the ideal goal there
are several obstacles against its introduction. DM
1) There is foremost an organizational problem. The administrations or enterprises which
have the task to collect and to update land related data have not been established un-
der the aspects of automation. They have no concern or jurisdiction for the data beyond
their area of competence: therefore they only intend to automate their own data flow.
2) There is also a technical problem. Discipline oriented administrations have hierachies
established beyond regions or states. The automation of their tasks favours the use of
control large size computers with complicated data bank software and many decentra-
lized terminals operated via the telephone network. Such a way of operation is severe-
ly limited by the data rate of transmission. This becomes particularly evident, if graphi-
cal data are to be administered.
3) A decentralized administration of graphic data. however. requires high investment
costs. which are not sensible for local administrations charged with limited tasks only.
This financial problem can only be overcome. if local data of several organizations
can be maintained in an integrated manner.
4) Finally, there exists a research and development problem. Administrations and organi-
sations involved in practical operations are according to their very nature not in the
position to be able to afford extensive research and development activities. Such acti-
vities can be better pursued by research institutes or universities, who are often not
given access to administrative problems on one hand, and who hesitate on the other
to deal with aspects of a non-analytical nature. Yet, in the interest to more actively
pursue to challenges of the profession a concentrated and coordinated effort of ad-
ministrations, technical organizations and academic institutions becomes necessary to
analyze the problem area in projects free from the limitations of specific organiza-
tional structures.
4. Pilot Project Neustadt am Rübenberge
For this reason the Institute for Photogrammetry and Engineering Surveys at the Univer-
sity of Hannover has embarked on a pilot project to study the methodology for data col-
lection for an integrated urban land information system over a limited area (B km?) in
the city of Neustadt am Rübenberge. about 20 km northwest of Hannover.
The City of Neustadt possesses a densely monumented control network established and
maintained by the State Survey Authorities. On the basis of this network numerical ca-
dastral data are available in form of field notes and up to date cadastral records.
These data are supplemented by an up to date cadastral map 1:1000. which is only defi-
cient in the display of certain topographic features.
It is possible to digitze the cadastral map with limited accuracy or to recalculate the
cadastral data with survey precision to create the cadastral graphic data base.
In order to obtain all topographic features of interest, it has been decided to use aerial
photography for the data collection.
Upon signalization of the control an aerial survey flight has been made of the area with
a 30 cm focal length camera at an image scale 1:3300.
In cooperation with Kern, Switzerland the following equipment and software has been uti-
lized to acquire digital topographic data. such as houses, vegetation, creeks, ditches,
fences and walls, lampposts, signs and utility manholes:
