EuroSDR Projects - Host Ireland

Figure 3-4: Sequence of manual photogrammetric point measurements for peaked roofs (BAE
Systems, 2000).
One of the best ways to extract complex features is to break them down into simpler components.
Thus, complex buildings were separated into several parts and combined later in AutoCAD (Figure
3-6). Due to the limitations of manual measurements, the photogrammetrically measured points were
not always homogenous, i.e. roof points were often not at the same height or the 3D models of the
extracted buildings were often not rectangular, which required a significant amount of manual
corrections of the 3D models in AutoCAD 2000 (Figure 3-7). Furthermore, separately measured
buildings parts were modelled and combined to one building (Figure 3-7).
Figure 3-5: Sequence of manual photogrammetric point measurement for gabled roofs (BAE
Systems, 2000).
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