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Research on gravity field modelling and gravimetry in Poland in 2019–2022

Krynski Jan, Dykowski Przemysław, Godah Walyeldeen, Szelachowska Małgorzata

Advances in Geodesy and Geoinformation

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2023

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Vol. 72, no. 2

art. no. e46, 2023

EN

The article presents the reviewed and summarised research activities of the Polish research groups on gravimetry and gravity field modelling in the period of 2019–2022. It contains the results of absolute gravity surveys for the maintenance of the international gravity reference level in Poland and Europe, and for geodynamic research with an emphasis on metrological aspects. It also contains relative gravimetry issues as well as the results of marine gravity surveys in the southern Baltic Sea. Non-tidal gravity changes were extensively investigated. Long-term gravity variations were monitored at the Borowa Gora Geodetic-Geophysical Observatory and in a few other locations in Poland. The contribution of gravimetric records to seismic studies was investigated. Temporal variations of the gravity field from GRACE (Gravity Recovery and Climate Experiment) and GRACE-FO (GRACE Follow-On) data, in particular, deformations of the Earth’s surface as well as temporal variations of heights, total water storage and groundwater storage were investigated. Moreover, GRACE-based products and the performance of monthly Global Geopotential Models (GGMs) were a subject of research. GGMs developed in last years were evaluated. The research on developing new approaches in geoid modelling and their validation was conducted. New regional and local geoid models were determined for Poland and Ethiopia. The use of different techniques for estimating the absolute sea level at sites of the selected network in the Baltic Sea was investigated.

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Merging the gravity fields of the GRACE Follow-On Science Data System project using different weighting approaches

Lenczuk Artur, Klos Anna, Bogusz Janusz

Advances in Geodesy and Geoinformation

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2023

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Vol. 72, no. 2

art. no. e42, 2023

EN

For over two decades, an essential information about global monthly gravity variations is provided by the GRACE mission and its successor, the GRACE Follow-On (GRACE-FO) mission. The temporal variations in gravity field from GRACE/GRACEFO are determined based on the measurement of distance changes between two identical satellites using microwave ranging instruments. This process is carried out by various processing centers, which adopt different processing strategies and background models. This causes discrepancies in the resulting gravity fields.We address this problem by determining a monthly homogenous GRACE-FO gravity field solutions from June 2018 to November 2022 as provided by different processing centers included in the Science Data System (SDS) project, i.e. the Center for Space Research (CSR), the German Research Center for Geosciences (GFZ) and the Jet Propulsion Laboratory (JPL). We test three different weighting schemes. We show that for the last 4 years, at least 65% of continental areas are characterized by water decrease. We show that proposed merged solutions contain more signal information than individual ones based on the square root of the degree variance values.We note that the largest signal differences between individual and combined solutions occur for sectoral coefficients up to degree 40, and for zonal coefficients, the signal differences are twice as small.We also present that the differences in the spherical harmonic coefficients cause differences in global and local equivalent water height (EWH) changes. For example, the proposed merged solutions reduce root mean square scatter ofEWHby 5–15% comparing to individual solutions.

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Wokół brachistochrony

Pochciał Jan

MINUT Matematyka i Informatyka na Uczelniach Technicznych

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2020

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Nr 2

63-77

PL

Praca przedstawia różne aspekty ruchu punktu materialnego w polu grawitacyjnym. W szczególności w oparciu równanie Eulera-Lagrange'a wyprowadza się równanie brachistochrony tj. krzywej realizującej najkrótszy czas ruchu oraz opisuje jej podstawowe własności i modyfikacje. Prezentowane treści ilustrowane są licznymi przykładami.

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The movement investigation of an axisymmetric rotation body under the action of electromagnetic fields

Hrevtsev O., Selivanova N., Popovych P., Poberezhny L., Shevchuk O., Hrytsuliak G., Poberezhna L.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 103, nr 2

67--77

EN

Purpose: To ensure an adequate level of accuracy, it is rational to study the ponderomotor forces of the ring, which drive a hollow disk of variable thickness, hung on the ring. Design/methodology/approach: The solution of the motion problem of a hollow disk of variable thickness suspended on a force ring of rectangular cross section is based on the method of solving the equations of the theory of thermoelasticity. The stress-strain state, as well as the motion of the specified body of rotation, the disk, in studies in a cylindrical coordinate system, under the action of ponderomotor forces. Findings: The motion equation of a hollow disk hung on a force ring-torus is made, exact solutions of the motion equations of a ring in the torus form of rectangular cross section are found. New component expressions of ponderomotor forces, which appear from the action of the ring's own electromagnetic field and cause the motion of a hollow disk, have been found on the basis of Maxwell's equations. It is proved that at high speeds and low natural accelerations the stress - strain state of the disk material does not cause the destruction of the structure. Research limitations/implications: Calculations of ponderomorphic forces are valid for the ring, which drives a hollow disk of variable thickness, hung on the ring. Practical implications: It is proved that at high velocities and small natural accelerations the stress-strain state of the disk medium does not cause structural damage. It is determined that the rotation in the direction of movement at an angle of 90 degrees changes only the direction of the acceleration vector without increasing its value. Originality/value: The dependences between own time and coordinate time are formulated. It is proved that a small change in the natural time for the studied disk can significantly change the coordinate time, and the pulsed electromagnetic field provides the ability to cover infinitely large distances over finite periods of time.

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Comparing variance of signal contained in the most recent GRACE solutions

Lenczuk Artur, Leszczuk Grzegorz, Klos Anna, Bogusz Janusz

Geodesy and Cartography

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2020

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Vol. 69, no. 1

19--37

EN

Gravity Recovery and Climate Experiment (GRACE) mission data is widely used in various fields of science. GRACE explored changes of the gravity field regularly from April 2002 to June 2017. In the following research, we examine variance of signal contained in two different formats of GRACE data: standard spherical harmonics and mass concentration blocks (so-called “mascons”) solutions, both provided in the most recent releases. For spherical harmonics-based solution, we use monthly gravity field solutions provided up to degree and order (d/o) 96 by three different computing centers, i.e. the NASA’s Jet Propulsion Laboratory (JPL), the German Research Center for Geosciences (GFZ) and the Center for Space Research (CSR). For the mass concentration blocks, we use values of total water storage provided by the CSR, JPL and the Goddard Space Flight Center (GSFC) computing centers, which we convert to spherical harmonic coefficients up to d/o 96. We show that using the anisotropic DDK3 filter to smooth the north-south stripes present in total wate storage obtained from standard spherical harmonics solution leaves more information than common isotropic Gaussian filter. In the case of mascons, GSFC solution contains much more information than the CSR and JPL releases, relevant for corresponding d/o. Differences in variance of signal arise from different background models as well as various shape and size of mascons used during processing of GRACE observations.

6

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

Krynski Jan, Dykowski Przemysław, Olszak Tomasz

Geodesy and Cartography

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2019

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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.

7

Rotation, initial stress, gravity and electromagnetic field effect on P wave reflection from stress-free surface elastic half-space with voids under three thermoelastic models

Abo-Dahab S. M., Rida S. Z., Mohamed R. A., Kilany A. A.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 1

313--328

EN

The present paper is devoted to investigate the influence of the rotation, thermal field, initial stress, gravity field, electromagnetic and voids on the reflection of P wave under three models of generalized thermoelasticity: Classical and Dynamical coupled model (CD), Lord-Shulman model (LS), Green-Lindsay model (GL), The boundary conditions at stress-free thermally insulated surface are satisfied to obtain Algebraic system of four equations in the reflection coefficients of various reflected waves. It is shown that there exist four plane waves; P1, P2, P3 and P4. In addition, the reflection coefficients from insulated and isothermal stress-free surface for the incident P wave are obtained. Finally, numerical values of the complex modulus of the reflection coefficients are visualized graphically to display the effects of the rotation, initial stress, gravity field magnetic field, thermal relaxation times and voids parameters.

8

Comments on "Archives of Civil and Mechanical Engineering 17 (2017) 564–573"

Pantokratoras A.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1643--1644

EN

The present comment concerns some doubtful results included in the above paper.

9

Propagation of a thermoelastic wave in a half-space of a homogeneous isotropic material subjected to the effect of gravity field

Abd-Alla A. M., Abo-Dahab S. M., Alotaibi H. A.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 3

564--573

EN

The propagation of thermoelastic waves in a homogeneous, isotropic elastic semi-infinite space is subjected to a gravitational field, which is at temperature T0 initially, and whose boundary surface is subjected to heat source and load moving with finite velocity. Temperature and stress distribution occurring due to heating or cooling and have been determined using certain boundary conditions. Numerical results have been given and illustrated graphically in each case considered. The results indicate that the effect of gravity field is very pronounced. Comparison is made with the results predicted by the theory of thermoelasticity in the absence of gravity. The results indicate that the effect of the gravity is very pronounced.

10

Problems and methods of calculating the Legendre functions of arbitrary degree and order

Novikova E., Dmitrenko A.

Geodesy and Cartography

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2016

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Vol. 65, no. 2

283--312

EN

The known standard recursion methods of computing the full normalized associated Legendre functions do not give the necessary precision due to application of IEEE754-2008 standard, that creates a problems of underflow and overflow. The analysis of the problems of the calculation of the Legendre functions shows that the problem underflow is not dangerous by itself. The main problem that generates the gross errors in its calculations is the problem named the effect of “absolute zero”. Once appeared in a forward column recursion, “absolute zero” converts to zero all values which are multiplied by it, regardless of whether a zero result of multiplication is real or not. Three methods of calculating of the Legendre functions, that removed the effect of “absolute zero” from the calculations are discussed here. These methods are also of interest because they almost have no limit for the maximum degree of Legendre functions. It is shown that the numerical accuracy of these three methods is the same. But, the CPU calculation time of the Legendre functions with Fukushima method is minimal. Therefore, the Fukushima method is the best. Its main advantage is computational speed which is an important factor in calculation of such large amount of the Legendre functions as 2 401 336 for EGM2008.

11

Gravity field modelling and gravimetry

Krynski J.

Geodesy and Cartography

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2015

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Vol. 64, no. 2

177--200

EN

The summary of research activities concerning gravity field modelling and gravimetric works performed in Poland in the period of 2011-2014 is presented. It contains the results of research on geoid modelling in Poland and other countries, evaluation of global geopotential models, determination of temporal variations of the gravity field with the use of data from satellite gravity space missions, absolute gravity surveys for the maintenance and modernization of the gravity control in Poland and overseas, metrological aspects in gravimetry, maintenance of gravimetric calibration baselines, and investigations of the nontidal gravity changes. The bibliography of the related works is given in references.

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Mitigation of Oceanic Tidal Aliasing Errors in Space and Time Simultaneously Using Different Repeat Sub-Satellite Tracks from Pendulum-Type Gravimetric Mission Candidate

Elsaka B., Ilk K. H., Alothman A.

Acta Geophysica

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2015

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Vol. 63, no. 1

301--318

EN

This contribution investigates two different ways for mitigating the aliasing errors in ocean tides. This is done, on the one hand, by sampling the satellite observations in another direction using the pendulum satellite mission configuration. On the other hand, a mitigation of the temporal aliasing errors in the ocean tides can be achieved by using a suitable repeat period of the sub-satellite tracks. The findings show, firstly, that it is very beneficial for minimizing the aliasing errors in ocean tides to use pendulum configuration; secondly, optimizing the orbital parameter to get shorter repeat orbit mode can be effective in minimizing the aliasing errors. This paper recommends the pendulum as a candidate for future gravity mission to be launched in longer repeating orbit mode with shorter “sub-cycle” repeat periods to improve the temporal resolution of the satellite mission.

13

Ewolucja modeli pola grawitacyjnego uzyskanych na podstawie misji satelitarnych

Kraszewska K., Kozakiewicz M.

Materiały Budowlane

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2013

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nr 11

65--66

PL

W artykule zaprezentowano wyznaczanie modeli pola grawitacyjnego z wykorzystaniem misji satelitarnych: GOCE, GRACE i CHAMP i pokazano, jak pomiary satelitarne wpłynęły na dokładność wyznaczenia kolejnych modeli w skali całego globu oraz obszaru południowej Europy.

EN

This article shall determine the subject matter of the gravity field models using satellitemissions: GOCE, GRACE and CHAMP. As shown in the satellite measurements affect the precision of the following models for the entire world and for the area of southern Europe.

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Badania grawimetryczne terenów naruszonych eksploatacją górniczą

Fajklewicz Z., Ostrowski C.

Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie

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2012

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nr 7

3-13

PL

W artykule przedstawiono rozwój metody mikrograwimetrycznej na przestrzeni ostatnich 30 lat, jej uwarunkowania metodyczne i możliwości prospekcyjne . Na kilku przykładach zaprezentowano wynik zastosowania badań mikrograwimetrycznych w zakresie rozpoznawania przypowierzchniowej warstwy ośrodka skalnego/glebowego. Szczególną uwagę poświęcono obszarom zdegradowanym działalnością eksploatacyjną i działanianiom zmierzającym do przywracania funkcji użytkowej terenom pogórniczym.

EN

The results of experiences at the application microgravity research for detection and exploration of the underground mining cavities done by the authors for 30 years are presented in the paper. The results several application are presented. The special attention was paid to postexploited mining ground surface in the parts of the inhabited regions. The satisfied result were reached for protection railways lines, main roads and highway. The microgravity researches are also very important for postexploited mining areas to restore them as a ground for building purpose.

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Wydajność mechanizmów modułu Parallel Computing Toolbox systemu Matlab w zrównoleglonej realizacji symulacji ruchu układów ciał w polu grawitacyjnym

Augustyn D.

Studia Informatica

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2010

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Vol. 31, nr 4A

33-74

PL

W pracy przedstawiono zrównoleglone programy symulacji wykonane w systemie MATLAB, pozwalające na ilustrację wpływu warunków początkowych na ruch ciała lekkiego w trójkątnym układzie trzech ciał ciężkich, uzyskanie zbioru torów złożonych układów N-ciał, prezentacje trajektorii ruchu wokół stabilnych punktów libracji Lagrange’a w ramach ograniczonego, kołowego problemu trzech ciał. Do implementacji wykorzystano mechanizmy modułu Parallel Computing Toolbox, m.in. takie jak: pętla zrównoleglona (parfor), komenda działająca zgodnie z koncepcją jednoczesnego uruchamiania tego samego kodu programu dla wielu danych (spmd), zadania wsadowe (jobs). Zastosowane metody zrównoleglenia symulacji pozwoliły na przyspieszenie realizacji zadań modelowania ruchu układów ciał w polu grawitacyjnym, uruchamianych na komputerach z procesorami wielordzeniowymi. W pracy dokonano porównania wydajności zaproponowanych programów symulacyjnych i użytych mechanizmów zrównoleglania obliczeń.

EN

The paper describes parallelized programs implemented in MATLAB designated for simulations of bodies movements in a gravitational field. They allow to illustrate hyper-sensivity a weightless body movement to initial conditions in the triangular system of 3 heavy bodies. Programs generate orbits for complex N-body systems. They present trajectories near stable libration points (Lagrangian points) for the circular restricted three-body problem. Some mechanisms of Parallel Computing Toolbox were used in simulation program implementations, e.g.: parallel FOR-loop (parfor), statement based on the concept – single program multiple data (spmd) and jobs/tasks. Those methods of parallelization let speedup simulations executed on machines with multi-core processors. The paper presents experimental results that show effectiveness of proposed solutions and applied parallelization methods.

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Investigations on the field of gravity in Polish tidal laboratories

Barlik M., Bogusz J., Kaczorowski M.

Reports on Geodesy

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2009

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z. 1/86

43-52

EN

Presently there are two laboratories in Poland investigating field of gravity. The Geodynamic Laboratory of Space Research Centre in Ksiaz is placed in the south-western part of Poland in horizontal galleries built in slope of the valley. In 1974 in the laboratory the measurements carried out with help of two quartz-horizontal pendulums equipped with photographic system of registration were begun. In 2002 in the laboratory the long water-tube tiltmeter was built. It is consisted of two perpendicular tubes 65- and 83-meter long, partially filled with water. In 2007 in the laboratory the relative gravimeter LaCoste&Romberg G-648 was installed. The Gravimetric Laboratory of Astro-Geodetic Observatory in Józefosław is placed in central part of Poland. It has been investigated tidal gravity changes since 1993 using first LC&R model G gravimeter, then D-model. Since 2001 laboratory is equipped with LC&R ET-26 meter. In 2005 the laboratory was equipped with FG5-230 gravimeter for monitoring of the absolute gravity variations. The paper presents current state-of-art of the researches aimed at investigation on field of gravity carried out by Polish scientific institutions.

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Czy mechanika kwantowa zagraża szczególnej teorii względności?

Sokołowski L. M.

Postępy Fizyki

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2009

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T. 60, z. 4

159-185

PL

Ostatnio pojawiły się sugestie, iż eksperymenty z cząstkami kwantowymi w stanach splątanych mogą wymusić znaczące zmiany szczególnej teorii względności. Tutaj rozpatruję tę kwestię z punktu widzenia relatywisty. Właściwa STW obejmuje twierdzenia geometryczne o czasoprzestrzeni Minkowskiego i nie wyklucza rozmaitych zjawisk biegnących z ponadświetlnymi prędkościami, których dopatrzeć się można w procesach kwantowych. Sama konstrukcja jakiejkolwiek czasoprzestrzeni wymaga ciał klasycznych, czyli agregatów kwantowej materii w stanach bliskich klasycznym. Ciała klasyczne są konieczne również w mechanice kwantowej, gdyż wymaga ona dualizmu: obiekt kwantowy - klasyczny przyrząd pomiarowy. STW opiera się na pomiarach na cząstkach kwantowych w stanach prawie klasycznych, z czego wynika, że fizyka cząstek elementarnych wymaga czasoprzestrzennej sceny o geometrii Minkowskiego i stany splątane nie mogą tej sceny naruszyć. Tym niemniej, w pełni relatywistyczny opis wielu procesów kwantowych napotyka poważne trudności. Są one wyraźnym sygnałem, że nasze pojmowanie teorii kwantów jest wciąż dalece niekompletne i teorię tę trzeba znacząco rozwinąć.

EN

Recently there appeared some suggestions that highly sophisticated quantum mechanical experiments involving entangled states might be a threat to special relativity and ultimately enforce deep modifications of the theory. Here we attempt to shed some light on the problem from the relativist's viewpoint. We emphasize what special relativity proper is: it consists of physically interpreted theorems concerning geometry of Minkowski spacetime and as such is compatible with a wide class of phenomena propagating at superluminal velocities. The very construction of a spacetime (Galilei or Minkowski) requires classical objects being quantum matter in quasi-classical states. These quasi-classical states are essential also for quantum mechanics, as is expressed in the dualism of the quantum object versus the classical measuring device. Special relativity is based on effects involving elementary particles and this shows that the quantum world necessitates Minkowski spacetime as the background, hence special relativity is robust. On the other hand a fully relativistic description of many quantum mechanical processes encounters a number of difficulties indicating that the current comprehension and interpretation of quantum theory is still incomplete and needs far reaching development.

18

GOCE

Królikowski J.

Geodeta : magazyn geoinformacyjny

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2009

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nr 4

8-9

19

GGOS information models: analysis of interrelations between observation techniques and the Earth gravity field

Pachelski W., Paśnicka-Pawłowska M., Szafranek K., Zwirowicz A.

Reports on Geodesy

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2008

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z. 2/85

61-70

20

Czarne dziury: odkryte w przyrodzie czy wymyślone przez człowieka?

Kijowski J.

Postępy Fizyki

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2008

|

T. 59, z. 4

146-153

EN

A short history of the general relativity theory (together with the theory of "black holes") is presented. A mathematical structure which enables us to describe gravitational field as a field of local inertial frames is proposed in a simple form. The notion of the curvature tensor is derived as an obstruction against existence of linear coordinates.