CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
439 
ucture 
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ents can be 
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irfaces with 
ition to one 
h-niodel is 
when it is 
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An initial 
g point co- 
ordinates. Central to this approach is the determination of 
unknown values. As a result the adjustment computation 
method was chosen. Characteristic of the resulting equation 
systems are their small size, resulting from the direct 
determination of unknown values. 
The determination of gradients is numerical. A modified 
Cholesky-approach with skyline-matrix is employed as 
fastsolver which has proven itself in the areas of geodesy and 
FEM. Initial tests use a continuous régularisation to improve 
the removal of singularities resulting from datum and 
configuration defects. A series of libraries resulting from the 
initial implementation were used as a basis for developing the 
first experimental prototype 'freak'. 
4. CONCLUSION 
A variety of different kinds of information must be obtained 
and organised during the early planning phases of a project that 
is relevant for later research and planning phases. However, at 
this stage planning documentation has not usually been drawn 
up to which this information can relate to. The common practice 
of commissioning an initial detailed survey is often too 
expensive as well as being time consuming. Moreover, the 
results do not always reflect the requirements of the planner or 
the researcher. Their information requirements are localised and 
are often successively intensified. 
An object-oriented approach for building surveying is proposed 
based upon a sketch-like iconic initial survey which can be 
progressively enriched with information detail. The objects and 
their inter-relationship is the central model rather that the 
geometry of the building. Different kinds of information can be 
related to building objects and made available to all the project 
participants. 
The implementation of the system was realised as a series of 
prototypes which communicate with one another using a 
common data model and working platform called freak. This 
system provides a model for a better organisation of 
information for all areas concerned with building conservation 
and World Heritage. 
5. REFERENCES 
Donath, D.: Die Auseinandersetzung mit dem Bauwerk - 
Notwendigkeiten im Planen und Bauen. IKM 2003, Weimar, 
Print in preparation. 
Donath, D., Petzold, F., Thurow, T.: Planning relevant survey 
of buildings - starting point in the revitalization process of 
existing building - requirements, concepts, prototypes and 
visions. The CIPA Archives for Documentation of Culture 
Heritage, Volume XVIII - 2001, pp. 565-572 
Petzold, F.: Computergestützte Bauaufnahme als Grundlage für 
die Planung im Bestand. Dissertation, Bauhaus-Universität 
Weimar, 2001