 This paper examined the intensity measurements taken with terrestrial laser scanners, TLS, and found that the range and incidence angle effects can be corrected for. The range effect was mostly due to instrumental factors, while the incidence angle effect was caused by the target's surface properties. However, further research is required to better understand these effects and develop more efficient ways to correct them. This article was authored by Antero Kuko, Miko Koselainen, Anci Crooks, and others.