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1.5 External Wall Numerical 
Data Processing 
A very good conformance between the exter- 
nal wall numerical data obtained from 
photograph and the rebuilt cenotaph design 
specification based on the basic design 
was ascertained. 
As can be seen from the contour map, the 
existing cenotaph has very well retained 
the symmetrical shape. On the basis of 
these two observations, the designer came 
to the conclusion to use the existing 
shape of the cenotaph without modifica- 
tion, as the exterior shape of the rebuilt 
cenotaph. 
However, the numerical photogrammetry data 
consists of height values at randomly 
selected positions which was defective as 
the data for 3-dimensional representation 
of perspective views, etc. 
To overcome this shortcoming,therefore, 
the height at all the intersections of a 
uniformly spaced grid set on the X-Y plane 
(10cm interval in X direction and 30em, in 
Y direction) were calculated by Lagrange's 
interpolation. 
1.6 Generation of Perspective View 
Perspective views are generated on the 
basis of the grid data for the exterior 
and interior wall surfaces. To allow the 
designer to recognize the shape of the 
object, 3-dimensional shapes are displayed 
on the graphic display screen with the 
effective combined use of the existing 
system possessing ordinary display fune- 
tions and a newly developed personal 
computer system adapted to special data 
processing. For more closer comprehension 
of the shape, detailed drawing wee plotted 
on an X-Y. plotter at a precision of 
o0.1mm. 
After thorough visual examination from 
various angles, the designer arrived at 
the following conclusions: 
(1) Interior Wall Surface Shape 
The interior wall surface shape formed in 
accordance with the rebuilt cenotaph basic 
plan was fully in conformance with the 
designer's concept and no modification was 
needed. 
(2)Exterior Wall Surface Shape 
As a result of the comprehensive observa- 
tion in combination with the interior wall 
surface shape and examination, no modifi- 
cation was found necessary. 
1.7 Generation of Numerical Data 
for Erection 
In the course of erection, wood patterns 
must be made before quarrying. For making 
wood patterns, numerical data are required 
for the exterior and interior wall sur- 
faces at each grid (30 cm in both X and Y 
directions) and for the masonry joint 
surfaces. The photos show numerical photos 
prepared by the CAD system for the quarry- 
ing planning and checking. 
1.8 Discussion 
To measure the exterior and interior wall 
surface shapes of the existing cenotaph, 
the terrestrial photogrammetry was adopted 
and in rebuilding the cenotaph to deter- 
mine the modified interior wall surface 
shape sulting to. the concept of the de- 
signer, the CAD system was utilized. 
The use of Photogrammetry was advantageous 
in the measurement of the shape of the 
existing cenotaph, particularly in the 
following respects: 
(1) The 3-dimensional shape of the ceno- 
taph was accurately and precisely measured 
and numerically represented. 
(2) Because of the many visitors during 
the daytime, the cenotaph was not accessi- 
ble for measurement. The orientation pints 
were set and measured during the night and 
the photographing was executed in early 
morning and in the evening when visitors 
were are scarce. The Photogrammetry al- 
lowed substantial reduction of site-work 
time compared with the conventional sur- 
veying. 
(3) The obtained images on photographic 
dry plates or film can be stored for later 
restoration and further reading of 3- 
dimensional data. Especially with the 
cenotaph which is a historical monumental 
object, this feature of data record stor- 
age is of special advantages. 
The use of the CAD system in the shape 
determination of the rebuilt cenotaph was 
advantageous mainly in the following re- 
spects: 
(1) Isometric projeetion 
The 3-dimensional display, perspective 
views and the slid models formed on the 
basis of the grids data as derived from 
the photogrammetrically obtained exterior 
shape and arbitrarily determined interior 
surface curves at the top area allowed 
easy comprehension and decision of the 
shape to the designer. 
(2) The joint use of a new CAD system 
based on personal computers with the 
existing system reduced the expense and 
time of the process. 
     
  
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Fig. 2 Cenotaph rebuilding 
basic plan