Jozsef Adam

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

Space very long baseline interferometry (SVLBI) is an extension of ground based VLBI to space, which has advantages, such as improving the precision and geometry structure of time delay observables with interconnecting multiple spatial coordinate systems directly. In this paper, a mathematical model of relativistic simulated SVLBI observables for e...

Water, which is present in the troposphere in all three phases, has a unique feature among atmospheric components. Besides the formation of clouds and precipitation, it has a key role in atmospheric energy transport and it is the most important greenhouse gas. Due to its temporal and spatial variability, the monitoring of water in the atmosphere re...

The GOCE satellite observes gravity gradients with unprecedented accuracy and resolution. The GOCE observations are reliable within a well-defined measurement bandwidth. In this study, different finite and infinite impulse response filters have been designed to obtain the demanded pass. Exhaustive time and frequency domain investigations prove that...

In this paper, a relativistic differential VLBI (ΔVLBI) mathematical model for Chang'e-l(CE-1) Transfer orbit is derived. Based on the model, A VLBI time delay observations are formed by differencing CE-1 time delay observations with a simulated radio source time delay observations. Then the error equation of observations is formed and the unknown...

In this paper, differential VLBI (ΔVLBI) model used for Chang'e-1 (CE-1) Transfer Orbit positioning is derived. Based on the model, error equation of observations is formed and coefficient matrix A is designed. Finally the influence of predicted accuracy of ERPs on CE-1 positioning accuracy is analyzed and some results are given.

In sum, the following activities were done: the IAG website was updated, improved and continuously maintained the IAG Newsletter was regularly issued monthly and distributed electronically, and selected parts of them were prepared to publish in the Journal of Geodesy as IAG News new version of the IAG Leaflet was prepared, printed and distribute...

IYPE activities of various geo-science associations, universities, research institutes and private companies in Hungary (www.foldev.hu) have been successfully coordinated by the Hungarian National Committee, which was established by the Hungarian Academy of Sciences, the UNESCO- and the IUGS National Committees. The National Launch Event (April 17,...

Three dedicated space VLBI projects are currently in preparation to launch one or more VLBI radio telescopes in orbits between 1992–1996. One in the Soviet Union called RADIOASTRON which is already an approved mission. The second one is a Western European mission called QUASAT with potential international participation. A consortium in Japan is stu...

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...

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...

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...

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...

In 1995, EUREF took over the task of the realization and maintenance of European vertical reference systems. The work started with the UELN project and one year later continued with the realization of the European Vertical Reference Network (EUVN). The EUVN is a static integrated network, at all EUVN points three-dimensional coordinates and geopote...

The paper deals with an integrated analysis of the environmental monitoring measurements made in the Sóskút geodynamic test network of the Department of Geodesy and Surveying of Budapest University of Technology and Economics (BUTE) in a period of two years (1999-2000). The results of the deformation analysis of the network and a detailed gravimetr...

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...

The unique radio astronomical technique of Space Very Long Baseline Interferometry (SVLBI) is an extension of the ground-based VLBI into the space. It has some important potential applications in geodesy and geodynamics, including the definition, practical realization, and interconnection of different reference frames, determining the geocentric po...

The Geodetic Institute of the University of Karlsruhe and the Department of Geodesy and Surveying of the Budapest University of Technology and Economics have been cooperating for 30 years in the field of deformation measurements and analysis. One of the common projects in this cooperation is related to the network of Sóskút which has been establish...

As a result of more than 5 years of research and development activities a permanent GPS station has been established at the Department of Geodesy and Surveying at the Budapest University of Technology and Economics (BUTE). This station is the second one in Hungary, the first one is operated by the Satellite Geodetic Observatory of the Institute for...

One of the first horizontal movement micronetworks in Hungary was established near Sóskút village in 1984. In this area there is a fracture, therefore there are 3-3 points at both sides of the line to detect horizontal and vertical movements. Within an academic project in the years 1999 and 2000 high precision geoderic (distance-, angle-, geometric...

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...

After a break of ten years, the work on the United European Levelling Network (UELN) resumed in 1994 under the name UELN-95. The objectives of the LJELN-95 project are to establish an unified vertical datum for Europe at the one decimeter level with the simultaneous enlargement of UELN as far as possible to include Central and Eastern European coun...

The first geoid computations in Hungary for positioning of a reference ellipsoid with respect to the new Hungarian triangulation network were performed in [2]. Homorodi produced a pure astrogeodetic geoid solution for only a small part of the country in Northern Transdanubia. The local geoid determination for Hungary covering its entire area has a...

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′...

The Second Continental Workshop on the Geoid in Europe (Budapest, Hungary, March 10-13, 1998) was organized in the Subcommision for the Geoid in Europe of the International Association of Geodesy (IAG) in co-operation with the Department of Geodesy, Technical University of Budapest (TUB), under the Sponsorship of the International Union of Geodesy...

Currently the European Geoid Project is on-going aimed at the determination of a Precise European Reference Geoid [Torge, 1992; Denker and Torge, 1993]. In Hungary we are strongly interested in the success of this effort toward a new European quasigeoid solution improved in spatial resolution and accuracy. Therefore appropriate gravity data and ele...

The purpose of this paper is to establish the optimum reference field as testing some geopotential model, gravity data and GPS data. We have to decide a best fitting geopotential model as a reference surface for establishing the optimum geoid solutions. We conduct some tests on the Korean Peninsula gravity data to establish which of the model would...

The purpose of this invited lecture is to present a global review and a general survey of the space VLBI missions, and to outline and to point at their potential applications in geodesy and geodynamics. Space VLBI, a simple extension of the existing geodetic technique of VLBI to space, would yield observables and data far beyond the scope of any ex...

For the purpose of local gravity field approximation, it is necessary to investigate which geopotential model describes the quasigeoid most closely in Hungary. Therefore, the ability of some high order geopotential models to recover the gravity anomaly field (Δ g) and height anomalies (ξ) in the Hungarian region has been tested. Two ways were used...

The Fast Fourier Transform (FFT) technique is an efficient and practical tool in geodesy for solving local gravity field approximation problems, among others for local geoid (quasigeoid) determination. In the future we plan to use the FFT procedure for its efficiency in computing a detailed gridded set of height anomalies for Hungary.

The feasibility of space very long base interferometry (VLBI) observables for geodesy and geodynamics is investigated. A brief review of space VLBI systems from the point of view of potential geodetic application is given. A selected notational convention is used to jointly treat the VLBI observables of different types of baselines within a combine...

In the next decade — the 90-es — dedicated radio telescopes will be launched into Earth orbit and will be integrated in the ground based Very Long Baseline Interferometry (VLBI) networks. Space-VLBI an emerging new observational technique will be with us.

Two dedicated space VLBI projects are currently in preparation to launch one or more VLBI radio telescopes in orbit between 1993-1996. One in the Soviet Union called RADIOASTRON is already an approved and funded mission. The second one is a Japanese orbiting VLBI mission called VSOP. There is a Western European mission with NASA participation in Ph...

A unique characteristic of space-VLBI for geodynamic studies is pointed out: space-VLBI provides a direct connection between the Conventional Inertial Reference System of extragalactic radio sources and geocentric reference systems of extragalactic radio sources and geocentric reference systems defined by dynamical methods respectively. New satelli...

The Finnish-Hungarian Doppler Observation Campaign, carried out in Finland during 13 days in August 1983, is discussed. It is shown that three Hungarian JMR-1A receivers and one Finnish JMR-4 receiver occupied 9 stations together with the first order triangulation network points of Finland. The processing of the data, performed in SGO, Penc, using...

The Euclidean spaces with their inner products are used to describe methods of least squares adjustment as orthogonal projections on finite-dimensional subspaces. A unified Euclidean space approach to the least squares adjustment methods “observation equations” and “condition equations” is suggested. Hence not only the two adjustment solutions are...

The Satellite Geodetic Observatory of the Hungarian Institute of Geodesy and Cartography is adopting and developing different programs of satellite orbit determination connected with its tracking activity /photographic, laser and Doppler observations/.

Simple cases of satellite and tracking station positioning have been considered which involve five or six Doppler stations tracking simultaneously and continuously during a single passage. The solutions have been reduced to the determination of socalled initial distances, because range-equations, instead of range-difference equations have been used...

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...

Kitűzött kutatásaink értelmében behatóan foglalkoztunk Magyarország geodéziai vonatkoztatási rendszereinek és vetületi síkkoordináta-rendszereinek alapkutatási színtű korszerű vizsgálataival. Széleskörű irodalomkutatás alapján feltártuk a gyakorlatban jelenleg is alkalmazott geodéziai vonatkoztatási rendszereink dátumparamétereit. Előkészítettük a...

Rövid összefoglalás A kutatási munka célja olyan GPS eszközök beszerzése, üzembe helyezése volt, amelyekkel a hidak építésének területén az építés-iányítási feladatok megoldása a korábban használt eljárásoknál korszerűbben valósítható meg. Ilyen módszerek alkalmazása nagy hidaknál a fejlett országokban már általános. A GPS berendezések által megter...

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...