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Research on general theory and methodology in geodesy in Poland in 2019–2022

Klos Anna, Ligas Marcin, Trojanowicz Marek

Advances in Geodesy and Geoinformation

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2023

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Vol. 72, no. 1

art. no. e40, 2023

EN

We present a summary of research carried out in 2019–2022 in Poland in the area of general theory and methodology in geodesy. The study contains a description of original contributions by authors affiliated with Polish scientific institutions. It forms part of the national report presented at the 28th General Assembly of the International Union of Geodesy and Geophysics (IUGG) taking place on 11-20 July 2023 in Berlin, Germany. The Polish authors developed their research in the following thematic areas: robust estimation and its applications, prediction problems, cartographic projections, datum transformation problems and geometric geodesy algorithms, optimization and design of geodetic networks, geodetic time series analysis, relativistic effects in GNSS (Global Navigation Satellite System) and precise orbit determination of GNSS satellites. Much has been done on the subject of estimating the reliability of existing algorithms, but also improving them or studying relativistic effects. These studies are a continuation of work carried out over the years, but also they point to new developments in both surveying and geodesy.We hope that the general theory and methodology will continue to be so enthusiastically developed by Polish authors because although it is not an official pillar of geodesy, it is widely applicable to all three pillars of geodesy.

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Model pływowy IERS2003 i ocena możliwości jego weryfikacji na podstawie wyników opracowania obserwacji GNSS

Bogusz J., Figurski M.

Biuletyn Wojskowej Akademii Technicznej

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2010

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Vol. 59, nr 3

421-441

PL

Niniejszy artykuł zawiera analizę możliwości korekcji pływowego modelu deformacji fizycznej powierzchni Ziemi opartego na standardach IERS2003, a wykorzystywanego w oprogramowaniu Bernese. Autorzy do tego celu wykorzystali stworzoną w Centrum Geomatyki Stosowanej Wojskowej Akademii Technicznej metodę opracowania precyzyjnych obserwacji geodezyjnych w ramach krótkookresowych rozwiązań sieciowych. Jako dane posłużyły obserwacje wykonywane na punktach sieci ASG-EUPOS otrzymane na mocy porozumienia pomiędzy WAT a Głównym Urzędem Geodezji i Kartografii. Analiza pływowa metodą najmniejszych kwadratów potwierdziła, iż model pływowy oparty o parametry matematyczne wymaga wprowadzenia współczynników geodezyjnych, szczególnie w częstotliwościach, które są trudne do zamodelowania, takich jak K1, K2 czy PSI1. W tych częstotliwościach analiza rezyduów obserwacji satelitarnych potwierdziła istnienie kilkumilimetrowych różnic. Otrzymany materiał stanowi świetną podstawę do badań zmian przestrzennych opisywanych parametrów i korelacji ich zmian np. z budową litosfery na terenie Polski.

EN

Present article contains the analysis of the possibility of introducing geodetic corrections to the IERS2003 tidal model. It is the model of the Earth's lithosphere tidal deformations used in the Bernese soft ware. The authors present the method of precise GNSS observations, processing in short-time intervals, which was worked out at the Centre of Applied Geomatics, Military University of Technology. As the data, the geodetic time-series (geocentric coordinates) obtained from satellite observations collected at the ASG-EUPOS sites were used. The tidal analysis based on the least squares method confirmed, that the model based on mathematical parameters requires the implementation of geodetic coefficients, particularly in frequencies which are difficult to be modelled such as K1, K2 or PSI1. In these frequencies, the residuals of satellite observations' analyses confirmed existence of the differences reached several millimetres. The results of this research state the ideal base for further investigations of spatial distribution of tidal deformational parameters and their correlation to the lithosphere's properties.

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A neural network relation of GPS results with continental hydrology

Ogaja C.

Artificial Satellites : Journal of Planetary Geodesy

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2006

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Vol. 41, No. 1

23--32

EN

This paper presents the application of a neural network methodology to historical time series of GPS data from the IGS (International GPS Service) network, based on terrestrial water storage information. Hydrology signals at the GPS sites are important for including water loading corrections in GPS data processing. However, it is quite common that a correct global water storage model may not be available for this purpose, due to lack of science data. It is therefore mostly assumed that water mass redistribution is one of the potential contributors to the seasonal variations in GPS station position results, particularly, in the vertical direction. Presently, the IERS Special Bureau for Hydrology (SBH) has archived continental water storage data from some of the latest model developments. Examples include the monthly (GRACE, NOAA CPC, NCEP/NCAR CDAS-1) and daily (NCEP/NCAR and ECMWF reanalyses) solutions. It is valuable to study the relationship between these solutions and long-term geodetic results, especially as the water storage models continue to be refined. Using neural networks offers an effective approach to correlate the non-linear input of hydrology signals and output of geodetic results by recognizing the historic patterns between them. In this study, a neural network model is developed to enable the prediction of GPS height residuals based on the input of NOAA CPC hydrology data. The model is applied to eight GPS sites with satisfactory results.