Analysis of vertical movements of the permanent GNSS station POLV on the base of satellite data and leveling

Abstract

The purpose of this work is to analyze the results of the study of the dynamics of vertical movements of the permanent station of the GNSS positioning system «Poltava» (identifier POLV). Method. A geodynamic test site was set up on the territory of the Poltava Gravimetric Observatory. It includes rappers with known stability indicators laid at different depths. The exact level of H‒05 is set on the A1 standard, which is characterized by high stability over 30 years of observations. The GNSS station, the vertical movements of which were studied, is installed on a specially built pedestal on the inner capital wall of the laboratory building of the Poltava Gravimetric Observatory of the S. I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine. The movement dynamics of the base station was monitored by marks placed on the edges of the western and eastern sides of the laboratory building. To evaluate and compare the obtained results, satellite data were processed by the method of approximation of polynomial smoothing of the third degree. According to the results of periodic geometric leveling, it was established that for the period 2004-2019, the slow vertical movements of the stamps were 1.03-1.11 mm with an average annual rate of rise of 0.065-0.07 mm/year. Seasonal vertical movements of the permanent GNSS station POLV are within 2 mm/year, and in the first half of the year, there is a rise of the point and a decline was in the second half of the year. Selected components that can affect the vertical movements of a GNSS station installed on an engineering structure. A comparison of ground and satellite observations results was made for the periods of 2004-2005 and 2018-2019. Based on the observations and modeling, the component of vertical oscillations of the receiving antenna obtained in the period of 2004-2005 by both ground and satellite methods did not exceed 2 mm; in the period of 2018-2019, the analysis of satellite data showed an increase in fluctuations up to 7 mm. This can be explained by a large spread of satellite measurements. Scientific novelty and practical significance lie in the detected stability of the amplitude of vertical movements of the GNSS station, which was confirmed by the ground method of geometric leveling and the analysis of the time series of satellite observations. The conducted studies confirm the influence of various factors on the stability of receiving antennas.