Monitoring of construction shape changes using reflectorless techniques

New total stations are equipped with two types of distance meters: IR (infra red) and (reflectorless). The option RL helps monitor the shape measurements of controlled surface of dozens of control points. It is possible to measure the distance directly to the object. The accuracy effects of using this system in precise measurements were controlled in laboratory and field conditions for reflective targets at different incidence angles. This paper presents the testing results and investigation conclusions concerning Leica TCRP 1202 and TCR 407 instruments.