This leads to σ0 = ( vTv/(n-u) )0.5, with u the number of parameters of F. In Fig. 4, left, the intensity values are plotted against range for Ex3 only. The curves for the targets of different reflectivity show the same features. For short ranges below 2m the recorded intensity grows, drops until 20m, and increases for longer ranges again. A similar behavior, featuring an increase in intensity for ranges up to 4m and a linear drop thereafter, was observed also for a Faro phase-based scanner