To facilitate the subsequent post-processing of the final
scans, a set of special scanning targets (see Fig. 4) were
deployed on fixed position and, before each scan, accurately
spatially targeted. These targets join partial point clouds into
a single unit in post-processing. These are 6 inch circular
targets coated with a highly reflective layer, precisely defined
centre and the possibility of rotating in both planar axes. It
allows focussing the target from any visible position. In mining conditions, characterized by poor light condition and high
dustiness, is sometimes very difficult to focus on targets due
to increasing distance from the scanning position and low
resolution of integrated camera and display. In order to
compare clouds of points from different scanning campaigns,
it is also necessary to place the targets in the equal positions.