5.3 Exhaust catalyst
The effective area of an exhaust catalyst is
depending upon the variations in height. The
surface is not solid enought for mechanical
profiling. The needle of a profiling device would
engrave the sufrace. By photogrammetric means
without contact to the object, this problem does
not exist. Figure 9 shows a profile crossing the
catalyst. Also this object has been determined
with an accuracy of £5um.
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Fig. 9: catalyst profile, length: 1.8mm
height with same scale like position
5.4 Examination of human bones
The fine structure of human bones is changing
over the years. The size of the tiny plates and
bars will be reduced. Such a complicate three-
dimensional object can only be measured by means
of photogrammetry.
3 m
T i |
y is 7) VUE
s m i X |
= a) =
n
RE
© M
(S 1
Fig. 10: height model of the finestructure of a
human bone, size: 1.25mm x 1.25mm
Fig. 11: finestructure of a human bone
size: 5mm x 9mm x 2.5mm
thickness of lines = f(z)
6. Conclusion
An accuracy of few microns in the object space
can be reached by macro photogrammetry. The
geometric stability of the used imaging systems
is limited. The orientation parameters have to be
calculated by the bundle method with
selfcalibration based on a threedimensional
control point body. The evaluation can be done
on-line with digital images and specialized
software or off-line with photos in analytical
stereo plotters. Totaly new areas of applications
have been opened.
Refrences
Jacobsen, K., Hielscher, H., Husen, B., Benter, U.:
Precise object determination by digital macro
photogrammetry, ISPRS, Com. V, Ziirich 1990
Jacobsen, K.: Off-line and on-line applications of
macro photogrammetry, ISPRS, Com |I,
Dresden 1990
Husen, B., Benter, U.:
using digital
Washington 1992
Precise tool measurement
photogrammetry, ISPRS
