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This paper presents the regional gravimetric survey of the central part of the Republic of Slovenia. The need for a new gravimetric survey, the survey plan and the actual field measurements are presented. Data processing, control calculations, data adjustment in the form of a gravimetric network and accuracy estimations of the results obtained during the regional gravimetric survey are described. Furthermore, the impact the new gravimetric data had on the quasigeoid model determined in 2016 and consequentially on determining normal height by GNSS levelling was analysed. The analysis were based on the comparison of the normal heights determined by GNSS levelling and the control points obtained from the 2010 and 2016 quasigeoid models. The results show that the new gravimetric data improved the newly calculated quasigeoid model or height reference surface of Slovenia and consequently made the determination of the normal heights by GNSS levelling more precise. The comparison of old and new height reference surfaces shows there are differences in investigated area from −6.9 cm to +9.0 cm and mean difference is 1.5 cm.

To perform geodetic measurements of displacements of the ground and manmade constructions, stabilised reference points are needed from which control points on the object or its surroundings could be measured. Reference points are most commonly stabilised with reinforced concrete pillars, however, they are not always constructed in an appropriate manner. The influence of temperature variation within a pillar on the position of the fixed screw for forced centring is not negligible and should be considered when performing precise measurements. In this research paper, the displacement of a pillar was calculated as a result of the temperature changes in the pillar, and then an experiment was performed in which the pillar was heated from one side, and the horizontal displacement of the fixed screw for forced centring was measured. Both, calculations and measurements, show that at a temperature difference of 16.2 &deg, C, the fixed screw on a 1.5 m high pillar moves by approximately 1 mm, which is a displacement that should be taken into account in precise measurements.

The paper presents all stages of the development and processing of the fundamental gravimetric network of Slovenia, which consists of a zero order network, which has six absolute gravity stations, and twenty nine first order gravimetric stations. Descriptions are given of the design of the network, the geological assessment of the gravimetric stations, the gravity survey of the first order network, and the post-processing and adjustment of the gravimetric observations, which was performed in two stages. First the observations in the zero order network were adjusted as a free network, and then a standard adjustment of the first order network was performed. Finally, the adjusted gravity values at the stations were analysed against the Potsdam system, which was the basis of all previous gravimetric calculations in Slovenia. In the analyses an equation for the transformation of gravity values between the Potsdam system and the IGSN71 system (International Gravity Standardization Network 1971) has been derived.

This paper deals with surveying activities in order to define the displacement of the Earth's crust, local displacements of the Earth's surface, and the displacement and deformation of constructed buildings. The determinations of horizontal movements in the terrestrial network, in the terrestrial altitude network and in the GNSS network are dealt with at two levels of accuracy. Geotechnical surveying activities are explained in the paper and demonstrated in the table. The paper Geodesy in geotechnics, published in Geodetski vestnik 54(1), and this paper present an integral whole.

Anomalies in vertical displacement rates related to recent geodynamics were determined between Rate~e and Ljubljana by comparing leveling line data with topography of the Sava river longitudinal profile. Beside the general trend showing increase of vertical displacement in the S-N direction, segmentation of the area is noted. The later suggests that active geological structures exist in the northern part of the Ljubljana basin and in the Upper Sava valley respectively.