The development of knowledge on geodynamic processes is one of the most important issues in the Earth’s science. Over decades, geodetic techniques have been applied to study the geodynamics. The Global Navigation Satellite Systems (GNSS) have been reliably used for monitoring geodynamic processes. The satellite gravimetric missions such as GRACE (Gravity Recovery And Climate Experiment) and GRACE Follow-On (GRACE-FO) missions have provided numerous valuable information concerning temporal mass variations within the Earth system which can subsequently be converted to surface deformations of the Earth. The main aim of this study is to compare vertical deformations of the Earth's surface over the area of SouthEastern Poland obtained from GNSS data with the corresponding ones determined from GRACE data. The GNSS data for the period between 2008 and 2013 from 25 permanent GNSS stations operating in South-Eastern Poland and the latest release of GRACE-based Global Geopotential Models (GGMs) were used. GNSS data and GRACE-based GGMs were processed with the GAMIT/GLOBK and the IGiK‒TVGMF (Institute of Geodesy and Cartography - Temporal Variations of Gravity/Mass Functionals) packages, respectively. The results obtained indicate that monthly vertical deformations of the Earth’s surface determined using GNSS data are generally in a good agreement with the corresponding ones obtained from GRACE satellite mission data. Coefficients of correlation between these vertical deformations range from 0.60 to 0.90 and standard deviations of their differences are in the range of 2.6 - 5.7 mm., Walyeldeen Godah, Malgorzata Szelachowska, Jagat Dwipendra Ray and Jan Krynski., and Obsahuje bibliografii
The dedicated satellite gravity missions have provided homogeneous and uniformly accurate information on the long and medium wavelengths of the Earth’s gravity field. Since the launch of GOCE satellite gravimetry mission by the European Space Agency (ESA) in 2009, several global geopotential models (GGMs) have been published. This study evaluates the recent GOCE-based GGMs over the area of Poland. The evaluation has been performed with the use of the EGM08 as well as high-precision GPS/levelling control traverse consisting of 184 stations. One GOCE-only GGM, four GOCE/GRACE satellite-only GGMs, and one GOCE/GRACE GGM combined with terrestrial gravity data have been selected for the evaluation. The results of inter-comparison of the models as well as their accuracy assessment have been discussed., Walyeldeen Godah and Jan Krynski., and Obsahuje bibliografii