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DEFINING THE FUTURE OF ARCHITECTURAL PHOTOGRAMMETRY
P. Waldhäusl
Institute of Photogrammetry and Remote Sensing
Vienna University of Technology, Vienna, Austria
Invited Paper, ISPRS Commission V, Working Group 5
ABSTRACT:
In classic times of architectural photogrammetry we have been limited to special cameras, special instruments and
special cases. Nowadays, photogrammetry is possible nearly with any camera, it uses more general instruments and
it is more flexible. Photogrammetry is going to be extended up to a real-time videogrammetry. Professional precision
photogrammetry needs more professionality than before, but it is also more powerful than before owing to the
potential of electronic data processing. Ground-(=object-) control can be reduced to a great extent by combined data |
adjustment. Cheaper cameras and simpler photogrammmetric systems are in use and will be further developed.
Powerful data bases are waiting for the data, their exchange, use and revision. It is time to redefine the future of
architectural photogrammetry as the most powerful tool to collect cultural and metric information about the
architectural heritage, but not only of two percent of it within hundred years as before, in future we have to speed
it up by a factor of 250 to get the job properly done, hopefully in time, i.e. within the next generation. !
KEY WORDS: Cultural heritage documentation, simple methods, international cooperation, CIPA
THE CHANGED TECHNICAL SITUATION
Since the last renaissance of architectural photo-
grammetry in the nineteen-sixties and -seventies the
methodology of terrestrial photogrammetry has changed
significantly. It is not limited to special cameras any
more. New, more universal and cheap cameras and
simple photogrammetric systems for restitution are
available and in use, and will be further developed. The
"normal case" is still economical and guarantees stere-
oscopy. But there has not been enough demand any
more for fixed base stereocameras, and thus they are
not being produced any more. In practice, we use in-
stead medium and small format, semimetric or even
non-metric cameras. Instead of strictly normal case we
use the nearly normal and the convergent case, but
with better base-distance-ratios. Additional oblique and
diagonal or cross shots form stable and accurate bundle
blocks (Schlégelhofer, 1989). Restitution with analytical
plotters after bundle block adjustment allows for a
maximum of flexibility and reliability. Ground-( = object-)
control can be reduced considerably, it is partly re-
placed by combined data adjustment. We have learnt to
reduce object control to a reliable minimum (Kotowski
et al., 1988, 1989; Waldhäusl/Peipe, 1990) and to
arrange photography in such a way that the interior
orientation can be determined simultaneously with
bundle block adjustment without any singularities
(Wester-Ebbinghaus, 1986). Analytical photogrammetry
doesn't work from image to map any more, but rather
from image to the monitor screen where the final edit-
ing is done prior to storage in data bases and/or output
on plotter. And plotting is not done any more at a pre-
determined scale, only, but at various scales as pre-
ferred for the practical tasks. The precision of meas-
urement has to be adapted to the requirements rather
than to a plotting scale. During the last years, digital
photogrammetry has been further developed. The digital
orthophoto is becoming daily practice (Ecker, 1991),
multiphoto image matching (Baltsavias, 1991) and new
digital cameras, scanners and a photoraster plotter
(Ecker/Jansa, 1989) promise a rather quick end of the
photographic age. Summarizing we see that photo-
grammetry and digital image processing have been and
will be further developed and that we have at our dis-
posal a much more powerful technology than ten or
twenty years ago.
Similarly, we recognize changes in the methodology of
the architects. They also work with computer graphics
and ask for the portability of data. Some architects
learnt to use photogrammetry by themselves, especially
with simplified technology as Rolleimetric or Elcovision,
and further systems will intensify this trend (Benning,
1992). As protection of environment has become one
767
of the main issues in the public, the architects have to
present, more and more, exact perspective simulations
of their projects prior to contracting, a task, which is
relatively new on the market.
The computerized photogrammetrical technology of
today needs more professionality than the rather simple
and specialized technology used in architectural photo-
grammetry in the past. In architectural photogrammetry
this higher professionality is not yet generally available.
Something must happen.
THE UNCHANGED DEMAND FOR ARCHITECTURAL
PHOTOGRAMMETRY
The "Convention for the Protection of Cultural Property
in Case of Armed Conflict" was a resolution of the
General Conference of UNESCO in The Hague in 1954.
Already in 1954 it was signed by fifty states and since
then by many more. The Convention was much too
late to protect the Indian architecture of the Americas
during the time after Columbus. It was also too late for
Warsaw, Le Havre, Dresden, and Hiroshima, towns, our
ancestors have built once with great effort for many
more generations to come. Iraq has signed the Conven-
tion and, in spite of that, Kermanshah and Kuwait have
been destroyed. Yugoslavia has signed the Convention
as one of the first countries. Article 132 of the Yugosla-
vian Penal Code stipulates that any person who orders
or who carries out the destruction of cultural property
or historical monuments, buildings or institutions dedi-
cated to science, art, or education or to humanitarian
aims ... shall be liable to imprisonment. In spite of that,
Dubrovnik, Sarajevo, Osijek, and Mostar and many
other places with ancient architecture have been de-
stroyed recently, in order to tear out the cultural roots
of the political enemy. - We still remember that in Ro-
mania the caterpillars have destroyed many of the old
villages, where generations have felt at home, and
replaced them by prefabricated mass silos. In Syria, 80
% of the Byzantine architecture, which has been regis-
tered still in 1910, disappeared until 1980; the old
palaces, churches and villas have been used as quarries,
where the poor - they have my sympathy - as well as
the rich took the stones to build up simple shelters and
rather primitive houses. In Vienna, Austria, and the
same in many European towns, the passion for the
modern as well as pure pursuit of profit destroyed more
than the Second World War did. The only difference: no
general massacres in these cases.
Other threats for the inherited architecture are earth
quakes, land slides, inundations, storms, conflagrations,
avalanches. Such events occur without prior notice. We
should be prepared for such events.
