In: Bretar F, Pierrot-Deseilligny M, Vosselman G (Eds) Laser scanning 2009, IAPRS, Vol. XXXVIII, Part 3AV8 - Paris, France, September 1-2, 2009 
282 
IMUs are substituted for low-cost micro-electromechanical sys 
tems (MEMS). 
Finally, variance information does not only indicate the quality 
of a scan process. It is an important component for the process of 
interpretation and analysing. In case of determining parameters 
of a model and relating stochastics, reliable input quantities are 
needed to get meaningful estimated parameters. 
The short scanning time of current laser scanners is ideally suited 
to scan objects multi-temporally. These data are often acquired 
from variable positions and different scanners. To compare the 
states, the distinct conditions have to be taken into account, if 
changes are to be evaluated stochastically. The additional in 
formation enhances the flexibility to process multi-temporal and 
multi-scaled laser scans. 
Future work aims to develop and investigate approaches of the 
unscented transformation and modifications of the incremental 
propagation to minimise the number of points where to calculate 
the Jacobian and Hessian. Besides the influences of scanner and 
referencing, further studies should include the scanning geome 
try. Therefore, an integrated mathematical model has to be set up 
including geometric parameters such as the angle of incident, etc. 
To consider more influences, the observation space has to be en 
larged. Thus, efficient variance propagation is necessary to re 
duce the increasing demands on computation - and to provide a 
basis for a qualitative processing of laser scanning data. 
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