EuroSDR Projects - Host Ireland

Used data Time use
Laser Aerial Ground Level of
Participant data images plan automation Espoonlahti Hermanni Senaatti Amiens
Cybercity 100 % low medium medium medium
Hamburg 100 % low medium high
Stuttgart 100 % low-high low low ?
IGN (Amiens) 100 % medium low
IGN (Espl, Her,
50 %
Sen)
50 % medium low low low
ICC laser+aerial 80 % 20 % low-medium high medium high
Nebel+Partner 90 % 10 % medium high high medium high
ICC laser 100 % low-medium high high high ?
FOI 100 % high low low low low
FOI outlines 100 % X high low low low low
C+B Technik 100 % X
mediumhigh
? ? ? ?
Delft 100 % X
mediumhigh
? medium
Aalborg 100 % X high ?
Dresden
? = not available
100 % X high low low
Table 3-1: Summary of used data, level of automation and time use of building extraction.
3.1.2 Building Extraction Methods
3.1.2.1 About method descriptions
Participants of the building extraction project were requested to describe the methods used for
building extraction. The authors have edited following process descriptions using these reports.
3.1.2.2 CyberCity AG
CyberCity used aerial images, camera calibration and exterior orientation information. Work was done
by experienced personnel.
CyberCity methods are based on concepts reported by Grün and Wang (1998a,b; 1999a,b) and
commercialization of the methods in CyberCity AG. The modelling is based on two steps. First,
manual photogrammetric stereo measurements are carried out using an in-house developed digital
photogrammetric workstation Visual Star. The point measurements are taken in a certain order and
points are attached certain codes using CyberCity's Point Cloud Coding System which will help the
more automatic process. Then, the resulting point clouds are imported into the main module CC-
Modeler, which automatically triangulates the roof points and creates the 3D building models. The
building footpoints and walls are generated by projecting and intersecting the boundary roof points
with the Digital Terrain Model (DTM). Alternatively, cadastral building footprints can be projected
back to the roof, which results in realistic roof overhangs and fulfills the consistency between 2D
cadastral maps and 3D city models. With CC-Edit geometric corrections can be carried out to get
accurate and correct 3D city models with planar faces and without overlaps or gaps between
neighboring buildings etc.
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