The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
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historical protected areas. The Historic Peninsula (Fig. 1) 
comprises an area of 1500ha with approximately 48,000 
buildings in crowded and frequently narrow streets (total length 
400 km). The facades of the building along the roads and streets 
cover an area of about 5,500 000 m 2 . In 2003 it was completely 
declared as a protected area, when urban protection plans at 
1:5000 and 1:1000 map scales were completed. For these 
protected areas detailed studies of urban design projects based 
on 1:500 and 1:200 map scales shall be carried out in the future. 
A project contract, briefly named as “Historical Peninsula 
project” was allocated to BIMTA$ by the Istanbul Greater 
Municipality’s Directory of the Protection of Historical 
Environment. Finally, due to the request of many municipality 
applications and due to an expected earthquake in Istanbul 
within the next 30 years BIMTAS, a company of the Greater 
Municipality of Istanbul, started the documentation of all 
buildings in the Historic Peninsula area by terrestrial laser 
scanning in 2006. It has been planned that the Historic 
Peninsula should be mapped in a time frame of two years, 
which demonstrates the great ambition of the project. 
The data acquisition of the Historic peninsula was carried out 
by terrestrial laser scanning for the building facades in the 
streets and for the building roofs by aerial photo flights with an 
analogue and a digital camera. 
3. DATA ACQUISITION BY TERRESTRIAL LASER 
SCANNING 
The data acquisition by terrestrial laser scanning started in 
September 2006 mainly using four Leica HDS4500. Figure 2 
shows an example of a coloured point cloud of building facades 
in the Historic Peninsula. 80ha of the project area (of 1500ha in 
total) was scanned within the first six months using the existing 
production capacity, which clearly indicated, that the scanning 
would need more than eight years for the entire project area, if 
this current scan rate of approximately 0.7ha per day could not 
be increased. 
calibration of the system in the streets of Istanbul took some 
weeks, but the data acquisition in the field has been working 
since the end of June 2007. The laser scanner was fixed with its 
orientation in the horizontal direction, scanning only in the 
profile perpendicular to the moving direction and operating 
with a speed of up to 40 profiles/sec. The distance between 
neighbouring profiles was 2-3 cm at the beginning, 
corresponding to a speed of the van during scanning of 
0.5m/sec up to 0.75m/sec or 1.8 km/h up to 2.7km/h. 
Figure 3. Sensor configuration on the mobile mapping van of 
VISIMIND AB 
Thus, the speed of data acquisition by terrestrial laser scanning 
was significantly increased through use of this mobile mapping 
system. Consequently, the laser scanning with the mobile 
system was finished by November, 8 th , 2007 with the improved 
total production rate of ~600m per hour, while post processing 
of the multiple sensor data took until January 2008. The 
production rate was mainly 1:10, i.e. for one hour scanning 10 
hours post processing of the data was needed. However, 
approximately 2% of the area (30ha) could not be scanned by 
mobile TLS due to traffic restrictions and environmental 
conditions. For the scanning of this remaining part static TLS is 
required. A more detailed description of the data acquisition by 
terrestrial laser scanning for the Historic Peninsula project is 
summarised in Baz et al.,(2008).' 
4. MAPPING OF FACADES 
The geo-referenced point clouds from laser scanning were used 
for line mapping of the facades at a scale of 1:200. The required 
positional standard deviation of 0.2mm on the map corresponds 
to 4cm in the object space as relative accuracy. The facade 
mapping was carried out by 34 operators using the Menci- 
software Z-MAP Laser from Italy, which is able to process laser 
scan data and rectified photogrammetric images simultaneously 
for line mapping with limited AutoCAD functionality. An 
example for the mapping of building facades with Z-MAP 
Laser is shown in Fig. 4. 
Figure 2. Coloured point cloud of building facades in the 
Historic Peninsula 
As a consequence the static scanning was replaced by mobile 
mapping through the Swedish company VISIMIND AB (Fig. 3) 
in June 2007 using a hybrid sensor system on the vehicle 
consisting of a terrestrial laser scanning system HDS4500, 
supported by GPS/IMU and digital cameras. This increased the 
scan rate dramatically. The sensor integration and the