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Research on reference frames and reference networks in Poland in 2019–2022

Krynski Jan, Liwosz Tomasz

Advances in Geodesy and Geoinformation

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2023

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Vol. 72, no. 2

art. no. e44, 2023

EN

The article presents the reviewed and summarised research activities of Polish research groups on reference frames and reference networks in a period of 2019–2022. It contains the results on the implementation of latest resolutions on reference systems of the International Union of Geodesy and Geophysics and the International Astronomical Union focusing on changes in the consecutive issues of the Astronomical Almanac of the Institute of Geodesy and Cartography, Warsaw. It further presents the status of the implementation of the European Terrestrial Reference System 1989 (ETRS89) in Poland, monitoring the terrestrial reference frame, including research on global terrestrial reference frames, GNSS data analysis within the EUREF Permanent Network, research on GNSS receiver antenna phase centres, research on impact of non-tidal loading effects on position solutions, and on station velocities. Then the activities concerning the realization of ITRS and ETRS89 in Poland are discussed, including operational work of GNSS IGS/EPN stations as well as operational work of the laser ranging station of the International Laser Ranging Service, with special emphasis on the Polish active GNSS network for the realization of ETRS89 and maintenance of the vertical control network. Extensive research activities are observed in the field of implementation of the International Terrestrial Gravity Reference Frame in Poland, maintenance and modernization of gravity control network in Poland but also in Sweden, establishment of gravity control network in Ireland based on absolute gravity survey as well as maintenance of the national magnetic control network in Poland which is traditionally performed on a regular basis.

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Research on reference frames and reference networks in Poland in 2015–2018

Krynski Jan, Rogowski Jerzy B., Liwosz Tomasz

Geodesy and Cartography

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2019

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Vol. 68, no. 1

5--29

EN

Research activities of Polish research groups in a period of 2015–2019 on reference frames and reference networks are reviewed and summarised in this paper. The summary contains the results concerning the implementation of latest resolutions on reference systems of the International Union of Geodesy and Geophysics and the International Union of Astronomy with special emphasis on the changes in the Astronomical Almanac of the Institute of Geodesy and Cartography, Warsaw. It further presents the status of the implementation of the European Terrestrial Reference System 1989 (ETRS89) in Poland, monitoring the terrestrial reference frame, operational work of GNSS permanent IGS/EPN stations in Poland, operational work of the laser ranging station in Poland of the International Laser Ranging Service (ILRS), active GNSS station network for the realization of ETRS89 in Poland, validation of recent ETRS89 realization, expressed in ETRF2000 in Poland, and maintenance of the vertical control in Poland (PL-KRON86-NH). Extensive research activities are observed in the field of maintenance and modernization of gravity control not only in Poland, but also in Sweden and in Denmark, as well as establishment of gravity control in Ireland based on absolute gravity survey. The magnetic control in Poland was also regularly maintained. The bibliography of the related works is given in references.

3

New high-precision values of the geodetic rotation of the major planets, Pluto, the Moon and the Sun

Pashkevich V. V.

Artificial Satellites : Journal of Planetary Geodesy

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2016

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Vol. 51, No. 2

61--73

EN

This investigation is continuation of our studies of the geodetic (relativistic) rotation of the Solar system bodies (Eroshkin and Pashkevich, 2007) and (Eroshkin and Pashkevich, 2009). For each body (the Moon, the Sun, the major planets and Pluto) the files of the values of the components of the angular velocity of the geodetic rotation are constructed over the time span from AD1000 to AD3000 with one day spacing, by using DE422/LE422 ephemeris (Folkner, 2011), with respect to the proper coordinate systems of the bodies (Seidelmann et al., 2005). For the first time in the perturbing terms of the physical librations for the Moon and in Euler angles for other bodies of the Solar system the most essential terms of the geodetic rotation are found by means of the least squares method and spectral analysis methods.

4

Reference frames and reference networks

Bosy J., Krynski J.

Geodesy and Cartography

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2015

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Vol. 64, no. 2

147--176

EN

The summary of research activities concerning reference frames and reference networks performed in Poland in a period of 2011-2014 is presented. It contains the results of research on implementation of IUGG2011 and IAU2012 resolutions on reference systems, implementation of the ETRS89 in Poland, operational work of permanent IGS/ EUREF stations in Poland, operational work of ILRS laser ranging station in Poland, active GNSS station networks in Poland, maintenance of vertical control in Poland, maintenance and modernization of gravity control, and maintenance of magnetic control in Poland. The bibliography of the related works is given in references.

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Układy odniesienia PL-ETRF89, PL-ETRF2000 i relacje między nimi

Kadaj R.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2015

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z. 62, nr 4

181--194

PL

Nowy układ odniesienia PL-ETRF2000, reprezentowany przez stacje systemu ASG-EUPOS, został wprowadzony do zastosowań formalnie Rozporządzeniem RM z 2012 r., jakkolwiek współrzędne stacji w tym układzie udostępniono dopiero w lipcu 2013r. Ze względu na powszechne korzystanie z serwisów ASGEUPOS, ważną kwestią stają się relacje pomiędzy nowym układem a istniejącym układem PL-ETRF89, który ma już w Polsce ponad 20-letnią historię – stosowany prawie we wszystkich „produktach” geodezyjno-kartograficznych. W zależności od zastosowania, wspomniane relacje mogą mieć charakter „teoretyczny”, wyrażony przez transformację konforemną (7-mio parametrową) lub „empiryczny”, oparty na siatce interpolacyjnej, która pozwala uwzględnić dodatkowo lokalne deformacje układu PL-ETRF89. Do tego ostatniego zadania, oprócz punktów sieci POLREF możliwe stało się wykorzystanie wyników nowego wyrównania dawnej sieci I klasy w układzie PL-ETRF2000. Po wprowadzeniu nowego układu odniesienia PL-ETRF2000 wystąpiła potrzeba skalibrowania modeli quasi-geoidy (anomalii wysokości) na nowe wysokości elipsoidalne. W użyciu praktycznym, chodzi o to, by niwelacja satelitarna wykonywana przy wykorzystaniu serwisów systemu ASG-EUPOS i modelu quasi-geoidy dawała wysokości normalne w układzie PL-KRON86-NH bez przesunięcia systematycznego. W pracy przedstawiono założenia i wyniki estymacji parametrów transformacji konforemnej pomiędzy układami, wskazując na potrzebę zastosowania tych formuł w przypadku integracji obiektów pochodzących z różnych układów odniesienia.

EN

The new reference frame PL-ETRF2000, represented by the stations ASG-EUPOS system was introduced for use formally by the Government Ordinance in 2012., although the stations coordinates in this system became available only in July 2013. Due to the widespread use of services ASG-EUPOS important issue is the relationships between new reference frame and the existed reference system PL-ETRF89, which has in Poland more than 20-years history – applied almost all most important geodetic and cartographic "products". Depending on the application, these relationships can be "theoretical", expressed by the conformal (7-parameters) transformation or "empirical", based on an interpolation grid, which allows to take into account additional local deformations of the PL-ETRF89. For this last task, in addition to POLREF network points it became possible to use the results of the new adjustment of the old national network of first class in the PL-ETRF2000 reference frame. After introducing the new reference system PL-ETRF2000, a need to calibrate the quasi-geoid models (height anomalies) on the new ellipsoidal heights occured. In practical use, the the point is that the satellite leveling performed using ASG-EUPOS system services and the model of quasi-geoid gave normal height in a PL-KRON86-NH without a systematic shift. The paper presents the assumptions and results of parameters estimation of conformal transformation between two systems, pointing to the need to apply these formulas in the case of integration of objects (e.g. geodetic networks) coming with different reference systems.

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The use of GPS data at T-T Zone for the verification of the recent terrestrial reference frames considering possible geodynamic processes

Godah W., Krynski J., Cisak J.

Geoinformation Issues

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2012

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Vol. 4, no. 1(4)

5--13

EN

The interpretation of the geodynamic phenomena with the use of GPS observations strongly depends on the quality of the terrestrial reference frame. The aim of this contribution is to verify station velocities from recent ITRF/ETRF solutions as well as to evaluate the possible geodynamic processes by using long time series of GPS data from four permanent GNSS stations operating in T-T zone. The components of four baselines were calculated with the use of the Bernese v.5.0 GPS software using GPS observation data from 2004–2012. Time variations of baseline components and baseline length were analysed and their linear trends were estimated by applying linear regression analysis. The obtained results have indicated that the variations are within the range from –0.2 to 0.3 mm/year in X–component, from –0.6 to –0.3 mm/year in Y–component, from –0.2 to 0.2 mm/year in Z–component and from –0.2 to 0.6 mm/year for the baseline length. The estimated linear trends of baselines components variations fit substantially better to the respective ones derived from ITRF2008/ETRF2000 (R8) than to the ones from ITRF2005/ETRF2000 (R5).

PL

Możliwość interpretowania zjawisk geodynamicznych na podstawie analizy obserwacji GPS w dużej mierze zależy od jakości ziemskiego układu odniesienia. Celem niniejszej pracy jest zweryfikowanie prędkości stacji uzyskanych ze współczesnych rozwiązań ITRF/ETRF, a także ocena ewentualnych procesów geodynamicznych przy użyciu długiego szeregu czasowego obserwacji na stacjach permanentnych GNSS położonych w rejonie strefy Teisseyre’a-Tornquista. Składowe czterech wektorów obliczono przy użyciu programu Bernese v.5.0 z obserwacji GPS z lat 2004–2012. Poddano analizie zmiany czasowe składowych tych wektorów oraz ich długości; przy wykorzystaniu analizy regresji wyznaczono trendy liniowe tych zmian. Rezultaty analiz wskazują na zmiany w przedziałach -0.2 do 0.3 mm/rok w składowej X, -0.6 do -0.3 mm/ rok w składowej Y, -0.2 to 0.2 mm/ rok w składowej Z oraz -0.2 do 0.6 mm/ rok w długości wektora. Wyznaczone trendy liniowe zmian składowych wektorów wykazują znacząco lepszą zgodność z odpowiednimi zmianami otrzymanymi z rozwiązań w układach ITRF2008/ETRF2000 (R8) niż ze zmianami z rozwiązań w układach ITRF2005/ETRF2000 (R5).

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The problem of temporal validity of reference coordinates in the context of reliability of the ETRS89 system realization in Poland

Szafranek K.

Artificial Satellites : Journal of Planetary Geodesy

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2012

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Vol. 47, No. 4

177--188

EN

The IAG (International Association of Geodesy) Sub-Commission for the European reference frame (EUREF) passed a resolution recommending application of the ETRF2000 frame as national realizations of the ETRS89 reference system during the XXth EUREF Symposium in Gävle (Sweden) in 2010. The PL-ETRF2000 system is comprised of EPN (EUREF Permanent Network) sites. Their coordinates and their temporal changes (velocities) were accurately determined on the basis of long-term GNSS observations. The transfer of the PLETRF2000 system onto the territory of Poland is realized by the ASG-EUPOS (Active Geodetic Network – European Position Determination System) permanent sites network. The ASG-EUPOS tasks include also system maintenance by continuous or periodical control of the coordinates and velocities constancy. According to the current Regulation of the Ministry of Administration and Digitization concerning geodesic, gravimetric and magnetic warps, the accuracy of sites of the fundamental warp (EPN sites belonging to ASG-EUPOS) may not be worse than 0.01 m for horizontal position and 0.02 m for geodesic height. It results in the necessity to monitor the performance of the reference sites for proper maintenance of the reference system. A new team for modeling deformations in Europe was established within the EUREF Working Group (The EUREF Working Group on Deformation Models) during the EUREF 2012 Symposium in Paris. One of its tasks is taking geo-kinematic models into consideration for national realizations of the ETRS89 and maximum usage of knowledge concerning the velocity field. The paper deals with the problem of temporal validity of the catalogue coordinates and the necessity of periodical updating them on the basis of velocities derived from long-term observations. Although Poland is located in a tectonically calm area and the intraplate velocities are small, some of the EPN and ASG-EUPOS sites have significant velocities and are subject to vertical movements. Lack of periodical updating of the coordinates realizing the reference system will cause lack of fulfillment of the assumed accuracy criterion. Analysis of horizontal and vertical velocities of sites belonging to the fundamental warp lead to assumption that two sites will exceed horizontal criterion in a period of time shorter than 10 years counting from the reference epoch (i.e. from 2011.0): KATO horizontal coordinates should be updated in 2014 and GWWL in 2021. Mores sites will exceed vertical criterion: BOGI (2021), GWWL (2015), KATO (2019), SWKI (2019) and ZYWI (2021). The vertical component updating will require of course changes of the horizontal component (coordinates are determined in the Cartesian orthogonal XYZ coordinate system and then recalculated for the ellipsoidal coordinates). Besides periodical coordinates updating it is recommended to conduct repeated processing for the entire network according to the EUREF standards for taking the current GNSS observations into consideration.

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The numerical solution of the Advection-Dispersion Equation: A review of some basic principles

Wallis S.

Acta Geophysica

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2007

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Vol. 55, no. 1

85-94

EN

The simulation of solute transport in rivers is frequently based on numerical models of the Advection-Dispersion Equation. The construction of reliable computational schemes, however, is not necessarily easy. The paper reviews some of the most important issues in this regard, taking the finite volume method as the basis of the simulation, and compares the performance of several types of scheme for a simple case of the transport of a patch of solute along a uniform river. The results illustrate some typical (and well known) deficiencies of explicit schemes and compare the contrasting performance of implicit and semi-Lagrangian versions of the same schemes. It is concluded that the latter have several benefits over the other types of scheme.