| Summary: | Levelling is one of the most important geodesic works in construction and other interventions in space. Mostly, it is used for the needs of the altitude presentations of the terrain, to determine shifts, to determine the height of the object, and for various precise laboratory and scientific researches. When determining the shifts, the values are confirmed with the results of levelling, and deformations are calculated. There are a lot of methods to determine height differences; which one will be used, depends on the complexity of the works. Recently, the GNSS method is mostly used. It offers 2D positionally reliable results, whereas the vertical component does not provide reliable results. For this purpose, a series of tests and GNSS-measurements analysis were performed at our institution, which is also presented in the article as the GNSS-measurements analysis in comparison to the results obtained with the robotic total station of accuracy 0,5ˇ. Prior to the experiment, a temporal GNSS data analysis based on an individual axis and with a different way of data processing was carried out. The planning of GNSS-measurements for the needs of more demanding measurements is emphasised. To improve the determination of the vertical component, the data capture with GNSS method was increased from 10 Hz to 100 Hz, which partly improved the final values and is presented in the study.
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