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SOME RECENT TYPICAL EXAMPLES IN INDUSTRIAL PHOTOGRAMMETRIC
APPLICATION WITH CAD TECHNIQUES
Taichi OSHIMA
College of Engineering
Hosei University
3-7-2 Kajinocho
Tokyo 184
Japan
Koganei,
Commission V
Abstract:
Recently, in addition to
computer-aided Geo-information
design(CAD) have been recognized as being very effective and
utilized to prepare basic data for decision making in administra-
tion and policy control in the field ob eivil engineering em-
ploying the photogrammetric method. This paper describes several
typical examples in the field of photogrammetry based on the GIS
and CAD systems.
remote sensing techniques, the
system(GIS) and computer-aided
Key Words: Close-Range, CAD, Traffic Accident,Perspective View
Calibration,Close-Range,Analytical Graphic Device.
1. 3-D Controlling Techniques using the
CAD System for Cenotaph restoration in
Hiroshima Peace Memorial Park by
Close-Range Photogrammetry
1.1 Outline
The cenotaph built in 1952 in the Hiroshi-
ma Memorial Park (atomic bomb site)as a
symbol of Hiroshima's prayer for world
peace has been damaged by years of outdoor
exposure and the city of Hiroshima has
decided to rebuild it in granite.
For this restoration, special considera-
tion is needed reviewing the following:
In the first place, because of the basic
concept of restoration of the existing
shape of the cenotaph, the existing shape
must be measured accurately and efficient-
ly by means of some non-contact method. To
meet these requirements, photogrammetric
method was used. In the second place,
because the structure will be changed
from the present reinforced concrete to
granite, the original sectional areas must
be modified to compensate for the reduced
strength and the shape of the interior
wall must be modified. In addition, since
the visual exterior wall shape must fully
represent the designer's concept, the
utilization of the CAD system capable of
3-dimensional representation was decided.
The investigation and analysis were
executed in accordance with these require-
ments mentioned above. Here are discussed
how the CAD system were used for the
restoration of the cenotaph based on the
3-D data by precise close-range photogram-
metry.
1.2 Photogrammetry
The close-range photogrammetric technique
was used for taking photos with at least 4
to 6 accurately measured control points
within a pair of photos. The stereoscopic
photographs are processed in a 3-dimen-
250
sional measuring device called the analyt-
ical plotter. The measuring points are
recorded and stored in computer. The
ground coordinates of the object are
obtained on the basis of the photographic
coordinates of the object by simple trans-
forming formula.
1.3 Photographing and Measurement
A single photogrammetric camera UMK10/1318
was used and in general the measuring
distance is selected between 3 to 10 times
of the base line length. A precision
analytical plotter of plans was used. The
intersection points of each pair of stere-
oscopie model can be checked by computer.
The residual errors of vertical parallax
was more or less 1 to 5 microns.
1.4 Application of CAD System
In the series of the cenotaph rebuilding
work, a CAD system was utilized for the
following purposes:
(1) the numerical data alone obtained
from the photograph process is not suffi-
cient to know the 3-dimensional shape
fully. Perspective view from any desired
viewpoints and other views must be dis-
played on the screen to allow the designer
to easily recognize the 3-dimensional
shape and to facilitate correction.
(2) As mentioned earlier, the new cenotaph
must have 14cm thicker wall at the middle
section for bulging inward than the exist-
ing shape. The new wall must have the
correct thickness and at the same time, it
must be visually satisfactory to the
designer.
(3) The quarrying process included in the
erection work required the wood patterns
and to make them, the numerical data for
any desired section is required.
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