ot finished)
mmetry Integration
Architectural
PA 2001
8-20 September
us Geländes, in
ndung
5, pp- 391-
.., Ahunbay, Z., —
bul Technical
stanbul, 2001. Pp.
'onservation of
> Period of Five Year
r, ITU Faculty of
nning Department,
enmeyer, P., Koehl,
)n Three-
ologic Approaches,
New Millennium,
NON-METRIC BIRD’S EYE VIEW
Prof. A. Georgopoulos, M. Modatsos
Lab. of Photogrammetry, Dept. of Rural & Surv. Engineering,
National Technical University of Athens,
9, Iroon Polytechniou, GR-15780 Greece - drag@central.ntua.gr
Commission VI, WG V/4
KEY WORDS: Non-metric aerial convergent photography, aerotriangulation, self-calibration, cultural heritage
ABSTRACT:
The combination of analytical photogrammetric methods and suitable software are a powerful tool for achieving almost the
impossible. For the geometric documentation of the Church of the Holy Sepulchre in Jerusalem a planimetric view of the rooftops
was required, among numerous other drawings. The complex of the main church and the surrounding buildings presented a rather
difficult object to survey either with classical survey methods. Hence a photogrammetric solution was sought.
Experience gained from other similar projects called for helicopter photography from such an altitude to ensure the necessary image
scale. As such a possibility was out of the question, oblique amateur non-metric photographs in colour slides were the only data
available. From a rigorous photogrammetric point of view, these data were completely useless for metric work. However, they were
forming a network of, mostly oblique, photos over the area of interest and — at the same time — a scientific challenge. At the same
time the work of the past years had already produced drawings of elevations and cross-sections of the monument, part of which
concerned the rooftops. Hence some distances between points in space could easily be extracted off these drawings. At the same
time, the BINGO-F software was also available.
This combination proved quite miraculous. Careful and suitable extraction of object distances, together with digitally measured
image co-ordinates were the observation data, which when introduced into the BINGO-F software supported the adjustment of the
whole network. The results of this adjustment were the exterior orientation elements of all photographs used, the geodetic co-
ordinates of a large number of characteristic points, which played the role of tie points. Interior orientation parameters were also set
as unknowns and the adjustment was able to produce their values. Several series of adjustments were performed in order to achieve
the desired optimum result. Numerous mathematical and geometrical parameters were tested and they were assessed according to
their effect. For the compensation of image errors the best self-calibration parametric model, different for each image available, was
sought and applied. From the adjusted co-ordinates of the numerous tie points, it was possible to compile the desired planimetric
drawing of the rooftops. In this paper the whole project is presented and the results are discussed for their accuracy and reliability.
1. INTRODUCTION as closters, mosques, shops, houses etc. The only façade
exposed is part of the Southern elevation, where the main and
1.1 History of the Project only entrance to the Church is situated.
For seven consecutive years the Laboratories of General 1.2 Administrative Problems
Geodesy and Photogrammetry of the Dept. of Rural &
Surveying Engineering of NTUA carried out the huge and
really challenging project of geometrically documenting the
Church of the Holy Sepulchre in Jerusalem. The project was
supported by the University of Athens, as far as the historic and
architectural documentation were concerned. This work was
realised under the auspices of the Greek Orthodox Patriarchate
of Jerusalem with the kind permissions of all other religious
Communities present in the area. For the completion of
fieldwork seven months, one each year, for the consequtive
years were needed. In the meantime processing of the collected
data was performed at home.
The geometric documentation comprised a series of drawings at
a scale of 1:50. Among them plan drawings at different levels
and elevations and at different locations through the monument.
One of the desired drawings was the horizontal plan of the roof
tops of the whole complex. It should be noted that the Church
of the Holy Sepulchre is situated in the Old Town of Jerusalem
and is surrounded by numerous buildings of various uses, such
The production of a roof top plan called for either aerial
photography (Georgopoulos et al., 1999) or access to the roofs
for intensive geodetic work. However, it was impossible to
apply any of the above solutions. Access to a large proportion
of the roofs of the Church was denied by the Muslims. This also
made difficult the survey of several objects for the elevations,
but it was rather easy to overcome the problem with terrestrial
photography and suitable measurements from a distance.
On the other hand, aerial photographs were only available, not
without serious red tape problems, at very small scales,
practically prohibiting the survey at the desired 1:200 scale.
Moreover, permission was not granted for taking our own
photographs from a helicopter, as local regulations would not
allow the craft to fly at heights lower than 1000ft. Hence it was
thought to abandon the production of this particular drawing.
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