anbul 2004
‘ocess. The
images.
ing on the
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aiming on
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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004
ent viewpoints is available. In order to connect point clouds
from different stations, frequently tie point information is pro-
vided using reflecting targets or spheres with defined diameter,
which are distributed in the object area. After measurement, the
operator manually specifies the approximate position of these
targets. Based on this information, the target can be precisely
localised automatically in the laser data and used as tie-point in-
formation in the subsequent registration process.
As it is demonstrated in Figure 10, this coregistration can
alternatively be performed based on a ICP (iterative closest
point) algorithm. By these means a coregistration of the laser
data to the coarse three-dimensional model of the building is
feasible. Thus, similar to the orientation of the collected images,
control point information is provided from the existing building
model in order to speed up the data processing. In principle, this
technique can also be used for the geoeferenceing of LIDAR
data collected from a moving platform (Früh & Zakhor 2003).
5. CONCLUSION
If existing urban models, which are frequently available from
airborne data collection are used for applications like realistic
visualisations of urban scenes from terrestrial viewpoints, a re-
finement using terrestrial data collection is required. The
evaluation of the terrestrial data can be simplified considerably
by integrating these existing building models to the respective
processing steps. Within the paper, the combined processing
was mainly demonstrated for geoereferencing the terrestrial data
sets by coregistration to the given models in order to provide
imge texture. However, this combined processing is even more
important, if terrestrial data sets are used for geometric im-
provement of the given models.
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