Gyula Toth

Gyula Toth
Budapest University of Technology and Economics · Department of Geodesy and Surveying

PhD

About

66
Publications
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289
Citations
Introduction
Skills and Expertise
Additional affiliations
September 1985 - present
Budapest University of Technology and Economics
Position
  • Professor (Associate)

Publications

Publications (66)
Preprint
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The motivation and research design for repeating the EPF experiments are described in the paper.
Article
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QDaedalus is an automated, computer-controlled astro-geodetic measurement system. Astronomical deflections of the vertical measured by the QDaedalus system are significantly influenced by atmospheric refraction. Therefore, the measuring system was further improved by recording the environmental parameters influencing the refraction (air pressure, t...
Article
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The Eötvös Pekár and Fekete (EPF) equivalence test was aimed to check composition dependence of the gravitational force. It was designed to be free from any bias related to the possibly time-varying ambient gravity field. Interestingly in 1986 Fischbach and his colleagues found a systematic composition dependency in the EPF data. This discovery ind...
Article
If the eyepiece of a total station is replaced with a CCD sensor, the most important task is to calibrate the instrument. Calibration establishes a connection between the readings on the horizontal and vertical circles of the total station and the readings in the coordinate system of the CCD sensor. Our calibration method uses a collimator in a few...
Article
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QDaedalus is an automated, computer-controlled astro-geodetic measurement system developed at ETH Zurich. This paper reports results of three years of deflection of the vertical (DOV) measurements with the QDaedalus system at Pistahegy, located in the SE part of Budapest. We analyzed inversion residuals for the angles measured by the total station...
Article
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Results of the Eötvös Pekár and Fekete (EPF) equivalence test were used by Fischbach and coworkers in 1986 as an argument in favor of a hypothetical fifth force. Although this hypothesis was abandoned in view of the negative experimental results that followed, we still miss plausible explanation of the EPF results. This situation motivated us to in...
Article
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The first gravity reference station of Hungary was established by Károly Oltay, professor and head of former Department of Geodesy, Technical University of Budapest. The station was located in the pendulum hall and its gravity value (g = 980 852 mGal) was derived in 1915 from relative pendulum measurements with respect to the reference station at G...
Article
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QDaedalus is an automated, computer-controlled astrogeodetic measurement system that has been developed especially for the determination of the local vertical deflections. We measured angles by the total station and recorded position of stars on the CCD. Then, by joint inversion of measurements we obtained the direction of the local zenith. We foun...
Conference Paper
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An updated gravity field model has been determined for Hungary using deflections of the vertical (DOV), gravity anomalies, quasigeoid heights by GPS/levelling and surface gravity gradients. Our solution methodology is least-squares gravity field parameter estimation using Spherical Radial Base Functions (SRBF) and regularization by Variance Compone...
Article
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Following the first big success in the 1910s and the second "Golden Age" in the 1950s torsion balance measurements for geological exploration have practically finished in Hungary by the end of the 1960s. After a long pause physical geodesy needed further measurements. Hence two Eötvös torsion balances manufactured previously has successfully been r...
Article
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The main problem of torsion balance measurements is the long damping time however it is possible to significantly reduce the observation time by modern technology. The damping curve can be precisely determined by CCD sensors as well as computerized data collection and evaluation. The first part of this curve makes it possible at least theoretically...
Article
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A new quasi-geoid model for Hungary was determined by combining gravity data, GPS/levelling and vertical deflections. Reduction of the measurements was performed by using Earth Gravitational Model 2008 (EGM2008) and Shuttle Radar Topographic Mission (SRTM) elevation data sets. Calculation method was Least Squares Collocation (LSC) with self-consist...
Article
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Effect of long-wavelength gravity field on the normal correction of the 1st order Hungarian Levelling Base Network – In view of the recent re-measurement campaign of the Hungarian Levelling Base Network we study the role of gravimetric observations. Adjustment of the network is performed using geopotential number, which can be converted into an equ...
Article
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After more than 40 years of interruption new field observations have been made by an E-54 type torsion balance (TB)in the Csepel-island. These TB measurements were accompanied by a detailed gravimetric survey of each station with LCR gravimeters. Both vertical (VG) and horizontal (HG) gravity gradients were determined at each TB station for VG inte...
Article
Before the end of the 1960s approximately 60,000 torsion balance measurements were made in Hungary. Recent research on the field of their geodetic applications showed the need for new observations. After an interruption of half a century, torsion balances are operated again in Hungary. Following the renovation and modernization of an Auterbal and a...
Chapter
Full-text available
A new quasigeoid solution HGTUB2007 was computed for Hungary using least-squares collocation technique for the first time by combining different gravity datasets. More than 300 000 point gravity data were interpolated onto a 1.5′× 1′ geographical grid consisting of 26, 478 values in the IGSN71 gravity system. The selected subset of these gravimetri...
Article
The Scientific Committee on Geodesy of the Hungarian Academy of Sciences has established an ad hoc comitte to overview the current status of the Unified National Height System (EOMA) and to formulate recommendations on the short and long term development of the height reference network in Hungary. The discussion paper prepared by the ad hoc committ...
Article
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A method was developed, based on integration of horizontal gradients of gravity W zx and W zy to predict gravity at all points of a torsion balance network. Test computations were performed in a typically flat area where both torsion balance and gravimetric measurements are available. There were 248 torsion balance stations and 1197 gravity measure...
Article
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The GOCE mission will produce gravity gradient data at satellite altitude and consequently contribute to more accurate determination of the gravity field. In a previous paper [10] we discussed formulas for the upward/downward continuation problem of second gravity gradients. The proposed approach was to use these gravity gradients in two combinatio...
Chapter
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Almost 100,000 surface gravity gradient measurements exist in Hungary over an area of about 45 000 km2. These measurements are a very useful source to study the short wavelength features of the local gravity field, especially below 30 km wavelength. Our aim is to use these existing gravity gradient data in gravity field modeling together with gravi...
Chapter
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In the space gradiometry the determination of the effect of topographic masses is crucial for the validation and downward continuation of the gravitational signal. This paper focuses on the determination of the effect of topographic masses on the second derivatives of the potential. During the investigation two methods are compared to each other. T...
Article
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CHAMP and GRACE global geopotential models EIGEN-3p, EIGEN-GRACE01S, GGM01S and GGM01C are compared with terrestrial gravity field data in Hungary. The methods used for comparison were direct comparison with gravity anomalies and the reference geoid solution method. We used free-air gravity anomalies interpolated on a 1′ × 1.5′ grid covering Hungar...
Article
Full-text available
The forthcoming GOCE mission will produce gravity gradient data at satellite altitude and consequently contribute to the more accurate determination of the gravity field. There are different data processing strategies in order to obtain updated gravity field information from these measurements, but most of them are based on the spherical harmonic e...
Article
The Internationale Erdmessung, predecessor of the IAG, held its General Meeting 100 years ago from September 20-28, 1906 at the Hungarian Academy of Sciences (MTA) in Budapest. This program was of historical importance for the discipline because it was here where the scientific community learned for the first time about the research activity of Lor...
Article
The Internationale Erdmessung, predecessor of the International Association of Geodesy, held its General Meeting 100 years ago from September 20-28, 1906 at the Hungarian Academy of Sciences (MTA) in Budapest. This program was of historical importance for the discipline because it was here where the scientific community learned for the first time a...
Article
Full-text available
Two case studies were considered where gravity field changes were detected resulting from water mass variations. The first case is an urban water reservoir where the maximum daily change of water is 40000 m3. The D model of the water mass allowed us to build an accurate polyhedral model of the variation of mass changes of the water. This mass densi...
Article
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Chapter
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There is a dense network of torsion balance stations in Hungary, covering an area of about 40000 km2. These measurements are a very useful source to study the short wavelength features of the local gravity field, especially below 30 km wave- length. Our aim is thus to use these existing torsion balance data in combination with gravity anomalies. Th...
Chapter
Full-text available
The forthcoming GOCE mission will provide gravity gradient observations along its orbit at varying altitude. It is necessary for certain data processing strategies to project the GOCE gravity gradients to a mean reference sphere. In the present simulation study the radial distance of the projection is in the order of 10 km, and can be done using th...
Chapter
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The vertical gravity gradients play an important role in the reduction of absolute gravity measurements and in the geoid determination, too. In order to enhance the precision of the gravity reductions and the geoid computations, the difference between the vertical gravity gradient of the real and the normal gravity fields should be taken into accou...
Chapter
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One promising method for the external validation and calibration of the upcoming GOCE satellite mission data is the use of ground gravity field data continued upward to satellite altitude. There is a unique situation for Hungary in this respect since surface gravity gradients are available at 20143 points over an approximately 48700 km2 area, measu...
Chapter
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The role of gravity gradients is investigated in the framework of geodetic-geodynamic boundary value problems. The time variation of the Eötvös tensor can be separated into three parts. The first part is a surface movement term, the second is the time variation of the gravity field in the original point, and the third is a coupling term. The first...
Article
The present state of geoid determination in Hungary was discussed by the Geodesy and Geodynamics' Subcommittee of the Scientific Committee of Geodesy of Hungarian Academy of Sciences. Results and future tasks of geoid determination are summarized in this paper.
Article
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The present state of geodetic applications of torsion balance measurements in Hungary has been discussed by the Geodesy and Geodynamics' Subcommittee of the Scientific Committee of Geodesy of the Hungarian Academy of Sciences. Results and future tasks of geodetic applications of torsion balance measurements are summarized in this paper.
Article
Full-text available
The forthcoming GOCE mission will produce gravity gradient data at satellite altitude and consequently contribute to the more accurate determination of the gravity field. There are different data processing strategies in order to obtain updated gravity field information from these measurements, but most of them are based on the spherical harmonic e...
Article
Full-text available
There is a long tradition of research on geodetic applications of Eötvös torsion balance measurements in Hungary. In the last century more than 60000 torsion balance measurements were made in Hungary, so this country has the most torsion balance measurements all around the world. At present serious efforts are going on for rescuing the former torsi...
Article
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The closed-form solution of a certain overdetermined fixed horizontal gradiometric bound-ary value problem is given in spherical, constant ra-dius approximation. The gravity anomalies are ex-pressed in terms of surface integrals of inner prod-ucts of the boundary data with vector and tensor val-ued Green's functions. The boundary data are the four...
Article
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Possible geodetic applications of Eötvös' torsion balance gravity gradient data were investigated in the present study. As a practical example gravity data have been predicted for two test areas in Hungary with the method of least squares collocation. By evaluating the results with gridded data interpolated from gravity measurements the standard de...
Article
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First the relevant theory of the interpolation and collocation methods is discussed, these two methods are used for the recovery of deflections of the vertical and geoid heights from torsion balance data. We have selected a mostly flat area in Hungary where all kind of torsion balance measurements are available at 249 points. There were 3 astrogeod...
Article
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Two test areas with different characteris-tics of the terrain were selected in Hungary to model the gravity field. We have used point gravity gradi-ents, their terrain effects and geopotential informa-tion to model geoid heights by numerical integration using kernel functions for specific gradient and cur-vature combinations which arise from the so...
Article
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The role of GPS technique for the determination of heights and height differences will increase in Hungary in the near future, too. The conversion of ellipsoidal heights (or height differences) from GPS into useful geodetic heights (or height differences) is a question of primary importance. Three types of heights are shortly reviewed. The differen...
Article
There is a long tradition of research based on Eötvös torsion balance measurements for geodetic applications in the Department of Geodesy and Surveying, TUB. We summarize in this paper the most important results of this long-term research.
Article
Some steps were taken recently for Hungary aiming at the determination of geoid heights with a cm-accuracy. The present HGTUB98 gravimetric solution was based on terrestrial gravity data, height data and the EGM96 geopotential model, and was computed with the 1D Spherical FFT method. The gravity data were used in the area 45.5 ° ≤ϑ ≤ 49 °, 16 ° ≤ λ...
Article
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Abstract Last year new,gravimetric datasets became available for geoid determination in Hun- gary based on more than 300 000 point gravity data compiled with and without topographic ef- fects. Some new DTMs were also created, since high- resolution global and local elevation data became available for public use in the last months. These datasets in...
Article
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Different local gravimetric geoid solutions were carried out in Hungary and the surrounding continental area. These solutions were based on terrestrial gravity data and height data using as a reference surface the EGM96 geopotential model. The gravity data used in the area 45.5° < φ{symbol} < 49°, 16° < λ < 23° were finally gridded on a 1.5′ × 2.5′...
Article
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When different map projection systems are applied simultaneously over a given area the need of conversion permanently arises in the overlapping areas of these systems. Conversions, however, can not always be made by closed mathematical formulas and in these cases it frequently raises serious problems to apply a correct transformation method. Hence...
Article
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The topographic-isostatic potential of the earth's crust can be computed easily using average crustal density parameters, a global isostatic model and a numerical dataset of mean continental and oceanic heights. In lack of the detailed data for density, crustal thickness and isostatic compensation, a least squares estimation is suggested to determi...
Article
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An important question in geosciences is the physical interpretation of global geoid forms and the improvement of our knowledge on the inner structure of the Earth. The authors suggest a new method which separates geoid heights due to upper known density inhomogenities from geoid heights of inner unknown mass distributions. The interpretation of rem...
Article
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Geophysical interpretation of the main geoid anomalies and exact knowledge of the inner structure of the Earth is an important question in geosciences. The authors suggest a new method which separates the computable geoid heights due to the topographical and all the known upper density distributions, from the unknown geoid originated from the deepe...
Article
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Vertical gravity gradients are measured in the field by gravimeters mainly for absolute gravity measurements but they are useful for gravity field determination as well. Using torsion balance measurements, however, it is possible to make a relative determination of vertical gravity gradients using an idea due to Haalck. Curvature values are differe...
Article
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At present 14 235 torsion balance data for Hun-gary are available at the Eötvös Loránd Geophysical Institute (ELGI) in digital form. These data are of good quality and we have used these data to recover various gravity field param-eters, such gravity and geoid for two test areas in Hungary. Least squares collocation and numerical integration by spe...
Article
Full-text available
Geodesy and Geodynamics. E-mail: (1) gtoth@geo.fgt.bme.hu, (2) volgyesi@eik.bme.hu ABSTRACT Torsion balance measurements in Hungary were checked by least-squares collocation. The methodology was the so-called "leave-one-out" prediction of horizontal gravity gradients. The method was successfully tested on a selected subset of 700 torsion bal-ance m...
Article
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1), L. Völgyesi (2), I. Cerovský (3) (1, 2) Budapest University of Technology and Economics, Department of Geodesy, H-1521 Budapest, Müegyetem rkp. 3, / Fax: +36-1463-3192. Research Group of Physical Geodesy and Geodynamics of the BUTE-HAS (1) gtoth@geo.fgt.bme.hu, (2) lvolgyesi@epito.bme.hu (3) Eberhard Karls Universität Tübingen, Institut für Geo...
Article
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Reconstruction of a torsion balance, and test measurements in the Mátyás cave in Budapest – During recent investigations concerning geodetic applications of torsion balance meas-urements several problems arose, which required performing new torsion balance measurements. For that reason the Eötvös-Rybár (Auterbal) torsion balance owned by the Depart...
Article
Full-text available
Possibility for reducing the measurement time of the Eötvös torsion balance – The main problem of torsion balance measurements is the long damping time, however it is possible to sig-nificantly reduce it by modern technology. The damping curve can be precisely determined by CCD sensors as well as computerized data collection and evaluation. The fir...
Article
Full-text available
Complex gravity field modelling in the Mátyáshegy Gravity and Geodynamic Observa-tory – What is the effect of cavities and rock masses above the Gravity and Geodynamic Observa-tory of ELGI on the observations? To answer this question a complex model was constructed con-taining all the rock masses and cavities as well as fixed mass elements inside t...
Article
A nehézségi erőtér időbeli változásával kapcsolatos kutatásaink során olyan lehetséges geológiai, geofizikai modelleket tanulmányoztunk, amelyek a nehézségi erőtér időbeli változásában szerepet játszhatnak. A nehézségi erőtér változásainak kimutatására illetve ellenőrzésére méréseket is végeztünk. A részben abszolút, részben relatív módszerrel végr...
Article
A vizsgálatainkat a magyarországi geoidmeghatározás, a geoidfelület interpoláció, továbbá a GOCE gradiométeres műhold jövőbeni méréseinek felhasználása főbb területein végeztük. Elvégeztük a kombinált geoidmegoldáshoz felhasználható adatok gyűjtését és rendszerezését, adatbázisba vitelét és az adatok vizsgálatát. Megfelelő számítási eljárásokat dol...

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