into 
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Boccardo, Piero 
4, RESULTS ACHIEVED 
The 3D model reconstruction can be easily performed thanks to the capability of the LMS-Z210 laser-scanner and the 
good potentialities of the post-processing software. No problems raised during the surveys neither in the image 
processing phase. The capability of the acquiring system to overpass glass surfaces (with high transmittance coefficient 
and refraction index) could be annoying for architectural surveying, particularly for object distance misplacement (all 
the features behind glass surfaces) and shift caused by the refraction coefficient. 
In order to test the metric accuracy of the laser-scanner takings, a digital orthophoto has been generated; in a second 
phase a stereo-restituted survey has been superimposed on the resulting image verifying the accuracy of the 
orthoprojected façade (figg. 18, 19). The tested accuracy is not more than 3 cm for each surveyed element; some 
discrepencies raise when height discontinuities are taken into account in the orthoprojection procedure, giving an 
“eroding” photographic effect. 
  
Figure 18 and 19 — Orthoprojected image (a zoom on the left) with the stereo-restituted survey (superimposed in 
white) 
4 CONCLUSIONS AND FURTHER DEVELOPMENT 
According to the authors the impressive capabilities of laser-scanner instruments (in terms of effectiveness, user 
friendliness and surveying time) can be the solution of a broad range of different problems in architectural 
photogrammetry, but also when other target has to be surveyed (for example in the evaluation of quarries volumes, civil 
infrastructures, and so on). 
In addition, the cost of the laser-scanner (approx. 100.000 DM), seems to be convenient for the huge application 
surveying spectrum; professional use (in particular if compared to standard total station price) could be mortgaged in 
few years of activity. 
Future studies should evaluate, in details, the metric accuracy of the system, in order to include this instrument class in 
future surveying specifications, taking into account particular capabilities of the device (for example the high resolution 
scan with doubled metric resolution).. 
ACKNOWLEDGMENTS 
We like to thanks for their kindness Mr. Johannes Riegl and Mr. Jürgen Nussbaum. Without their aid, these tests can 
not be performed. 
REFERNENCES 
P. Waldhaeusl, A test object for architectural photogrammetry: Otto Wagner's Underground station Karlsplatz in 
Vienna, in XIV CIPA International Symposium, 2-5 October 1991, Delphi, Greece, pagg. 247-251 
Internet Web site WWW.RIEGL.COM 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000. 75