Božo Koler

The new fundamental gravimetric network of Slovenia

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.

Geodesy in Geotechnics

Geodetic methods are one of the possible means of determining the stability of geotechnical objects. The determination of the displacements of the geotechnical objects is specific due to the size and the expected displacements. The expected size of the displacement determines the necessary precision of the displacement determination, whereas the size of the object determines the method of the geodetic measurement. We choose either the terrestrical or the GNSS methods. There is no relevant legal framework for geotechnical measurements. For this reason, we present the characteristics of the single methods and suggest general recommendations regarding the implementation of the geodetic procedures when monitoring the displacements of the geotechnical objects. The recommendations are intended for geotechnical engineers planning the geotechnical objects and the operators of geodetic measurements and investors. The recommendations the facilitate supervision of the geotechnical projects.

Analysis of different height systems along the sava river

The paper presents a project of renovating a levelling line from Hydroelectric Power Plant Medvode to Hydroelectric Power Plant Vrhovo. The levelling line is situated along the Sava River. A new height of benchmark was needed as a vertical reference system for the project building up a new HPP between the previously mentioned HPP. Further, the paper presents processing data on measurements (scale and temperature corrections). Gravimetric measurement was performed due to the determination of the geopotencial number and dynamic and normal heights. Slovenian official vertical system contains normal orthometric heights so we also calculated normal orthometric heights. Moreover, the article discusses the accuracy of measurements (levelling and gravimetric) and analyses height calculated in different vertical systems and vertical movements along the levelling line.