To investigate the potential mixing of range and incident angle effects in TLS intensity measurement and data, we scanned the 4-step calibration plate (Spectralon Inc) at distances of 1, 5 and 10 meters. The plate was tilted from vertical to horizontal
orientation with 5⁰ steps. The distance effect was corrected using a intensity vs. distance function based on data from our
previous laboratory measurements (see Kaasalainen et al., 2011 for further information).