International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
  
a) 3 x 3 inch flat 
  
c) halfsphere 
magnetic mount 
   
b) 6 inch circular flat 
Figure 3. Cyra Targets 
4.2 Data Processing 
The data processing was carried out exclusively in the Cyclone 
software modules. The first step of the processing was the 
transformation of all point clouds from the local scanner 
coordinate system into the common coordinate system 
(registration). This processing step was performed in the 
Cyclone software by a 3D Helmert transformation without a 
scaling factor (CYRA 2003b.) A strict adjustment with identical 
points is not provided in the software. 
Three processes are available for the registration of point 
clouds: Firstly, all point clouds could be registered using only 
suitable overlap areas with a precision of 8mm; Secondly, the 
registration can be supported by the use of ten targets as tie 
points, which are scanned from different stations (the mean 
distance to these matched targets (tie points) was Imm); 
Finally, the transformation of the point cloud into the local 
geodetic network could be performed by eight scanned control 
points, which were determined with a standard deviation of 
Imm using a total station. However, six targets, which were 
well distributed in object space, were used as check points. On 
average the difference from the check point coordinates, which 
were determined by the total station, was better than Smm. 
  
Figure 4. 3D Laser Scanning System CYRAX 2500 at Boie Lübeck 
Scanning and registration were carried out as an automated 
process using the Cyra targets (Fig. 3). These targets were 
already recognized semi-automatically by the software during 
the scanning phase. Unfortunately, the construction of the 
Cyrax 2500 as a camera view scanner with a limited field of 
view was a disadvantage for the measurement of long stretched 
pipelines, which required several additional scans, each with an 
overlap of 1/3 of the scanning area. 
Finally, a 3D CAD model of the pipelines (Fig. 6) was 
generated from the registered and geo-referenced point cloud. 
For the evaluation, single parts of the point cloud were selected 
manually to approximate geometrical primitives (in general 
cylinders) in the selected and processed data. The thus 
generated single CAD elements were subsequently bound to a 
complete 3D model. Using check points measured with a total 
station a precision of better than 10mm could be achieved for 
the 3D model. The processing time needed for the generation of 
the 3D model was 111 work hours in total. 
5. RECORDING OF THE HOLSTENTOR LUBECK 
5.1 Data Acquisition 
The recording of the Holstentor in Lübeck was carried out in 
the local scanner coordinate systems, i.e. no Cyra targets were 
used for registration and geo-referencing of the point clouds due 
  
Figure 5. Pipelines of company Boie in Lübeck 
Figure 6. Same p: ^lines modelled in CAD. 
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