In: Wagner W., Szekely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
292 
Figure 7. Shading of the geometry-based roughness (left) and of 
the mean echo widths (right); dz < 0.5 m. Black areas are 
nodata raster cells. 
Such roughness layers are valuable input datasets for further 
analyses as for example shown in Aubrecht et al. (2010) but 
also directly for a multitude of process models and simulations. 
In future research the influence of varying flying heights and 
incidence angles on the echo width is investigated. 
Furthermore, the increasing uncertainty with weak signals, 
resulting in low amplitudes, will be studied. 
ACKNOWLEDGMENTS 
The presented research was funded by the Austrian Research 
Promotion Agency (FFG) in the frame of the Austrian Space 
Applications Program (ASAP). The airborne laser scanning data 
was provided by the MA 41 Stadtvermessung, Wien. 
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