Abstract
Observations of land surface deformation are one of the important tasks of surveying, especially in landslide areas. They concern the determination in time of the magnitude of the deformation, on the basis of a stable reference system based on a geodetic control points. The whole measurement process can be divided into two parts. One part concerns the observation of reference points (geodetic control points) and the other the observation of the object itself. In the first, in addition to classical methods, GNSS (Global Navigation Satellite System) techniques based on reference stations are used. In the second, common observation methods such as laser scanning or photogrammetric methods using Unmanned Aerial Vehicles (UAV) are used. These observations are carried out in a specific time period in relation to the aforementioned geodetic control points. An area such as Kadzielnia in Kielce is covered by a long-term observation programme. A key element is the survey of the constancy of the geodetic control points, which are located in the epicentre of the survey. The survey of the constancy of the control points at Kadzielnia was based on a static method using SmartNet stations. Taking into account the fact that reference stations are treated as error-free reference points and that they operate 24 hours a day, it was decided to study the variability of their position over a longer period of time, as well as to determine the influence on the geodetic control points and to observe the deformation of the object during the measurement cycles.