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The assessment of the results achieved in our division at the field of physical geodesy is summarised. The studies at the fields of Earth rotation, Earth tides, Earth gravity and the global and regional Earth deformations related to geodesy and geodynamics are presented by citation of the most important publications and dissertations, which cover the history of our institute. The paper ends with the case study related to the newly developed full roving GPS observation strategy.

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The basic idea behind selective multiscale reconstruction of functions from error- afiected data is outlined on the sphere. The selective reconstruction mechanism is based on the premise that multiscale approximation can be well-represented in terms of only a relatively small number of expansion coeficients at various resolution levels. An attempt is made within a tree algorithm (pyramid scheme) to remove the noise component from each scale coefilient usinga priori statistical information (provided by an error covariance kernel of a Gaussian, stationary stochastic model)

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Abu-Dabbab area is characterized by high seismicity and complex tectonic setting, for these facts, a local geodetic network consisting of eleven geodetic benchmarks has been established. The crustal deformation data in this area are collected using the GPS techniques. Five campaigns of GPS measurements have been collected, processed and adjusted to get the more accurate positions of the GPS stations. The horizontal velocity vectors, the dilatational, the maximum shear strains and the principal strain rates were estimated. The magnitude of the movements is distributed inhomogeneous over the area and it varies in average between 3 and 6 mm/yr. The results of the deformation analyses indicate a significant contraction and extension across the southern central part of the study area which is characterized by high seismic activity represented by the clustering shape of the microearthquakes that trending NE-SW direction. The north and north-eastern parts are characterized by small strain rates. This study is an attempt to provide valuable information about the present state of the crustal deformation and its relationship to seismic activity and tectonic setting at Abu-Dabbab area.

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The paper gives an overview of recently considered concepts and methods for gravity inversion from the orbit of a Low Earth Orbiter (LEO). In this study only noiseless simulations were performed. The study aims to introduce these methods and to demonstrate their feasibility for High-Low Satellite-to-Satellite Tracking (SST) concerning the forthcoming GOCE satellite. Further conclusion on the efficiency of these methods within the scope of this study will not be provided.

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Some interpolation and smoothing techniques have been analyzed for velocity and acceleration determination from kinematic LEO (Low-Earth Orbiter) orbits. Tests were performed on a simulated GOCE orbit and on a kinematic CHAMP orbit as well.

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The development of star cameras started in the 1970s. Their purpose was the determination of astronomic position. Using photogrammetric method, the fieldwork could be carried out quickly. The accuracy was reduced compared to the traditional methods, yet the overall time needed for measurement and processing decreased drastically. In the 2000s, some of these instruments were fitted with CCD sensors. Automatized data processing methods were developed, which provided superior speed and accuracy. Recently, the development of a simplified star camera system has been started at the HAS-BUTE PGG. In this paper some key steps of the processing of the measurements are outlined. Many of these steps can be regarded as optimization problems. For this purpose, the Differential Evolution was chosen as a fitting algorithm.

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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 Hungary. In the second method these geopotential models were used to compute gravimetric geoid solutions and the results were compared with GPS/leveling data from EUVN campaign and the Hungarian GPS network. 

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In the 20th century more than 60000 torsion balance measurements were made in Hungary. At present efforts are made to rescue the historical torsion balance data; today 24544 torsion balance measurements are available for further processing in computer database. Previously only the horizontal gradients of gravity were used by geophysicists, but there is a good possibility in geodesy to interpolate deflections of the vertical, and to compute geoid heights from curvature gradients of gravity. First the theory of the interpolation method is discussed, than results of test computations are presented. We have selected a test area where all kinds of torsion balance measurements are available at 249 points. There were 3 astrogeodetic points providing initial data for the interpolation, and 10 checkpoints for controlling the results. The size of our test area is about 750 km2 and the average site distance of torsion balance data is 1.5-2 km. The standard deviations of geoid height and deflection of the vertical differences at checkpoints were about ±1-3 cm, and ± 0.6'' respectively; which confirm that torsion balance measurements give possibility to compute very precise deflections of the vertical and local geoid heights at least for flat areas.

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