International Archives of the Photogrammetry, Remote
Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
e
ce &
| @
|
Ld ol
A
12,4
ES
eo 2
x S
11,6 | 9,9 | 12,2
| |
33,6
>
Figure 11. Results of the 2D post processing: section, view and ground plane of the Holstentor in Lübeck
6. ECONOMICAL ASPECTS
Although it is fascinating to look at the projects from the
technical and realisation point a view, it is absolutely necessary
to check the projects from an economic perspective. All
processing steps could be accomplished with a standard PC
(256 MB RAM, 1.4 GHz AMD Athlon processor). In Fig. 12
the total processing time needed for each individual processing
step for each project is represented. In summary a ratio of 1:9
for data acquisition to data post processing could be achieved
for both projects. If more post processing is necessary due to
more requested details in the 3D model the ratio would
increase. It could be clearly seen in Fig. 12 that scanning needs
only approx. 20% of the project time, whereas the remaining
80% is used by registration and geo-referencing of the point
clouds and by intensive post processing for the generation of
the requested products. Thus, the measuring system permits the
fast and comprehensive production of object-related measuring
data. Furthermore, the scanned object can be virtually taken to
the office in form of point clouds. Usually, details are rarely
forgotten during the data acquisition due to the automated high
resolution scanning of the objects.
7. RESULT AND OUTLOOK
In conclusion, in two different projects it was demonstrated,
that the tested terrestrial laser scanning system is suitable for
detailed 3D data acquisition and object modelling. The 3D laser
scanning system Cyrax 2500 has been proven to be stable and
simple to use. The level of detail, which can be set by the scan
grid during the data acquisition phase, depends on the
requirements of each application. The precision of the
processed data is lem in Cyclone and 2cm in AutoCAD. This
achieved precision could fulfil the requirements of the
presented applications. Due to its measuring accuracy, its high
point density, and its measurement speed laser scanning
increasingly represents an alternative to and/or an additional
option for geodetic and photogrammetric data acquisition
methods. In particular, the use of the Cyrax 2500 for the
recording of outdoor applications can be recommended
although the camera-view scanner has a restricted field of view.
In contrast to the outdoor use of the scanner, it would not be
very efficient to use the CYRAX scanner for indoor
applications because of the narrow field of view.
946
Int.
Fi
[n tl
ben
in tl
scan
geor
deve
the c
a GF
the |
proc
of th
beco
also
betw
contr
the le
Boeh
[
p
Cyra,
(^
Cyra,
St
js
Grün,
ni
Grün,
Te
Jahn,
U
de
lis
H:
Johan:
dij
bu