Wyniki wyszukiwania - Biblioteka Nauki

1

Validation of European Gravimetric Geoid models in context of realization of EVRS system in Poland

100%

Marjańska D. , Olszak T. , Piętka D.

Geodesy and Cartography

|

2019

|

tom Vol. 68, no. 2

329--347

EN

In this study, several variants create and choose of a local quasi-geoid model in Poland have been considered. All propositions have a source in European Gravimetric Geoid models – EGG2008 and EGG2015, which are purely gravimetric models of reference surface. In the course of this work, each model has been analyzed in various ways: without any corrections, by parallel shifting of residuals, by the 7-parameter conformal transformation and by fitting residuals by 4- and 5-parameter trigonometric polynomials. Eventual corrections were based on points of national GNSS/levelling networks (EUVN, EUVN_DA, POLREF, EUREF and ASG-EUPOS eccentric points). As a final result of this study, a comparison of the accuracy of selected models has been carried out by RMSE statistics and maps showing spatial distribution of residuals and histograms. Validation has shown that the maximum achievable accuracy of the EGG models is approximately 2 cm for the ETRF2000 reference system and approximately 8 cm for ETRF89. In turn, fitting with the use of different mathematical methods results in an improvement of the standard deviation of residues to the level of 1.3–1.4 cm. The conclusions include an evaluation of considerations for and against the use of models based only on EGG realizations and, on the other hand, fitted to the points of Polish vertical network. Its usefulness is strictly connected with needs of the definition of up to date quasi-geoid model for the new realization of heights system in Poland, based on EVRF2007 frame.

2

Research on gravity field modelling and gravimetry in Poland in 2015–2018

100%

Krynski J. , Dykowski P. , Olszak T.

Geodesy and Cartography

|

2019

|

tom Vol. 68, no. 1

31--63

EN

Activities of the Polish research gSDroups concerning gravity field modelling and gravimetry in a period of 2015–2018 are reviewed and summarised in this paper. The summary contains the results of research on the evaluation of GOCE-based global geopotential models (GGMs) in Poland and geoid modelling. Extensive research activities are observed in the field of absolute gravity surveys, in particular for the maintenance of national gravity control in Poland, Sweden, Denmark, the Republic of Ireland and in Northern Ireland as well as for geodynamics with special emphasis on metrological aspects in absolute gravimetry. Long term gravity variations were monitored in two gravimetric laboratories: the Borowa Gora Geodetic-Geophysical Observatory, and Jozefoslaw Astrogeodetic Observatory with the use of quasi-regular absolute gravity measurements as well as tidal gravimeter records. Gravity series obtained were analysed considering both local and global hydrology effects. Temporal variations of the gravity field were investigated using data from GRACE satellite mission as well as SLR data. Estimated variations of physical heights indicato the need for kinematic realization of reference surface for heights. Also seasonal variability of the atmospheric and water budgets in Poland was a subject of investigation in terms of total water storage using the GLDAS data. The use of repeatable absolute gravity data for calibration/validation of temporal mass variations derived from satellite gravity missions was discussed. Contribution of gravimetric records to seismic studies was investigated. The bibliography of the related works is given in references.

3

Modernization of the basic gravimetric control network Polish Geological Institute - implementing a modern international gravimetric system and relationship with the historical Potsdam system

75%

Olszak T. , Rosowiecka O. , Musiatewicz M. , Targosz P. , Kulpiński M. , Krupa P. , Stefański M.

Reports on Geodesy and Geoinformatics

|

2024

|

tom Vol. 117

1--10

EN

The project of the gravimetric database reambulation from the collections of the Central Geological Archives set itself the goal of ending the era of gravimetric bases dualism and transferring both databases: gravimetric base and archival gravimetric semi-detailed measurements to the modern frame of gravity reference, consistent with ITGRS/F definitions and realizations. This will strengthen the interpretational potential of gravimetric data and will open the possibility of fully integrating Polish gravity data with international databases of this type, and will also allow for the performance of modern works in relation to the modern gravimetric control network, i.e., in relation to the highest possible precision of the reference definition of gravimetric measurements in the country. Whenever the article refers to the units in which the gravity vector is determined, milliGal [mGal] is used, and the relation to the SI system is as follows: 1mGal = 10–5ms–2 or microGal [µGal] where 1µGal = 10–8ms–2.