Fig. 3
Schematic overview of the laser scan acquisition, processing and products. (a) Laser scans were initiated by a time-scheduled command computer with online weather information. (b) A global geo-reference transformation matrix was determined by matching reflectors (red dots, (b) upper image) in a scan of the laser scanner (blue dot) with GNSS measured reflectors in real space (b, lower image). (c) A time-dependent fine alignment transformation matrix for each epoch was obtained by comparing each Nth scan (upper figure c) with the first scan of the acquisition period (lower figure c). (d) Application of both transformations to a scan results in various georeferenced products.
