Also influences on the intensity values and their standard
deviation could be detected. In contrast to the theoretical 1/r2
,
the mean intensities decrease only slightly with longer distances
(up to 25m). A stronger decrease is caused by increasing
incidence angles, most materials approximately according to the
cosine-law with exception of the Spectralon® targets where an
increase up to 20gon can be observed. Wetness condition has a
strong effect on the received intensities for building materials
(about a factor of two). Therefore, a classification of objects or
object parts based on intensity values seems to be difficult –
especially for surfaces with unknown reflectivity. Such tasks
may be suitable for industrial applications in defined
environment. The standard deviation σI
of intensity values
increases with higher reflectivity. Therefore, white surfaces and
surfaces in the colour of the laser deliver highest σI
values.