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Start Over Subject geofyzika Type články

2. Coherence between geophysical excitations and celestial pole offsets

Creator:
Cyril Ron and Jan Vondrák
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geofyzika, geophysics, geophysical excitations, celestial pole offsets, coherence, 7, and 551
Language:
English
Description:
Celestial pole offsets are the displacements between the observed position of the Earth’s spin axis in space and its position predicted by the adopted models of precession and nutation. At present, the models are IAU2006 and IAU 2000, respectively. The celestial pole offsets are regularly measured by Very Long-Baseline Interferometry (VLBI), the observations being coordinated and published by the International VLBI Service for Geodesy and Astrometry (IVS). These offsets contain a mixture of several effects: the unpredictable free term, Free Core Nutation (FCN) that is due to the presence of the outer fluid core of the Earth, forced motions excited by the motions in the atmosphere and oceans, and also imperfections of the adopted precession-nutation models. The geophysical excitations are also available, as determined by several atmospheric and oceanographic services. The aim of this paper is to compare the time series of these integrated excitations with the observed celestial pole offsets and estimate the level of coherence between them., Cyril Ron and Jan Vondrák., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Determination of intermediate orbit and position of glonass satellites based on the generalized problem of two fixed centers

Creator:
Władysław Góral and Skorupa, Bogdan
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geofyzika, geophysics, GLONASS, orbit determination, problem of two fixed centers, 7, and 551
Language:
English
Description:
The mathematical model and algorithms for calculating the position of GLONASS satellites by means of their broadcast ephemeris is presented in the paper. The algorithms are based on the generalized problem of two fixed centers. One of the advantages of the analytical solution obtained from the generalized problem of two fixed centers is the fact that it embraces perturbations of all orders, from the second and also part ly from the third zonal harmonics (Aksenov, 1969). GLONASS broadcast ephemeris - provided every 30 minutes - contain satellite position and velocities in the Earth fixed coordinate system PZ-90.02 (ICD, 2008), and acceleration due to luni-solar attraction. The GLONASS Interface Control Document recommends that a fourth order Runge-Kutta integration algorithm shall be applied. In the Department of Geomatics (AGH UST) a computer program has been established for fitting position and velocity of GLONASS satellites using their broadcast ephemeris. Intermediate GLONASS satellite orbits are calculated consider ing also the second and third zonal harmonics in the gravitational potential of the Earth. In this paper results of the analytical integration of the equation of the motion of the GLONASS satellites compared to the numerical solution are provided., Władysław Góral and Bogdan Skorupa., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Determination of near-surface apparent resistivity by means of high frequency mutual impedance measurements

Creator:
Beziuk, Grzegorz and Mydlikowski, Remigiusz
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geofyzika, geophysics, geophysical method, loop antennas, mutual impedance, apparent resistivity, 7, and 551
Language:
English
Description:
A method of determination the apparent resistyvity of the ground’s near-surface la yers from measurements of the mutual impedance of a loop antenna system operating at a high frequency is presented. An analysis of the sensitivity of mutual impedance to variation in the parameters of conducting half space at different frequencies had been carried out. Additionally influence of displacement current on measured mutual impedance values was discussed. A frequency of measuring system was selected in order to obtain a high sensitivity of the measuring system to detection inhomogeneities characterised by small dimensions and low apparent resistyvity contrast. The measuring system and the method of interpreting measurement results were described. The results of field measurements were presented., Grzegorz Beziuk and Remigiusz Mydlikowski., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. First results of conical borehole strain gauge probes applied to induced rock mass stress changes measurement

Creator:
Staš, Lubomír, Kamil Souček, and Jaromír Knejzlík
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geofyzika, geodynamika, geophysics, geodynamics, stress measurement, stress tensor, conical gauge probe, stress changes, 7, and 551
Language:
English
Description:
Using of shaped conical borehole bottom to determination of the stress tensor changes induced by changing of geomechanical situation is described in this paper. The measured strain changes on gauge probe are caused not only by the stress changes evocateg by progress of long wall. The some deformation started imediatelly after instalation when the long wal didn't move. In paper are discussed the eventu alities of this phenomenon too., Lubomír Staš, Kamil Souček and Jaromír Knejzlík., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Geodynamic network Sněžník: reprocessing and analyses of satellite data in the Czech part over the period 1997-2011

Creator:
Otakar Švábenský, Josef Weigel, and Lubomil Pospíšil
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geofyzika, geodynamics, geophysics, GNSS, recent movement tendencies, Sněžník metamorphic unit, 7, and 551
Language:
English
Description:
Latest studies of recent geodynamic movements going on major geological structures of the Sněžník metamorphic unit are closely related to geodetic satellite measurements, especially to permanent and ep och GNSS satellite methods. For this reason the Institute of Geodesy, Faculty of Civil Engineering, Brno University of Technology (IG FCE-BUT) continues measurements in Local Geodynamic Sněžník Network (LGSN) which was established in 1992 in Czech-Polish cooperation for the purpose of lithosphere movement monitoring. A special attention was devoted to detection of possible displacements of the local blocks of Králický Sněžník Massif. The results confirm the significant horizontal and vertical movements within relatively small territory. All these and other detected contemporary geodynamic phenomena are presented and discussed., Otakar Švábenský, Josef Weigel and Lubomil Pospíšil., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. Geological constraints on the GPS and precice levelling measurements along the Diendorf-Čebín tectonic zone

Creator:
Lubomil Pospíšil, Otakar Švábenský, Josef Weigel, and Witiska, Michal
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, nivelace, GPS sítě, geodynamika, geofyzika, leveling, GPS netwoks, geodynamics, geophysics, Morava (Česko), Moravia (Czechia), Diendorf fault, Boskovice Furrow, Moldanubian, Brunnia units, 7, and 551
Language:
English
Description:
In the contribution geological structure and geophysical data along the northern part of the Diendorf-Čebín tectonic zone (DCTZ) is analyzed in relation to the position of the measured GPS test areas and precise levelling profiles. For this purposes the former geophysical data have been reambulated and analyzed, too. Revision of geological knowledge and sources has been done in places of the proposed polygons. The results of reinterpretation of the Grav/Mag data and selected seismic reflection profiles suggest new possibilities and variety of structural interpretations of this tectonic zone. It is evident that the whole tectonic system has undergone complicated tectonic development during the Paleogene and Neogene. Therefore the recent mapping and analyses by GPS and precise levelling have to be realized in places where the geological structural ambiguity has to be eliminated., Lubomil Pospíšil, Otakar Švábenský, Josef Weigel and Michal Witiska., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Movement tendencies in the Moravia region: kinematical model

Creator:
Pospíšil, Lubomil, Otakar Švábenský, and Josef Weigel
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodezie, GPS (navigační systém), geofyzika, geodesy, GPS (navigation system), geophysics, Morava (Česko), Moravia (Czechia), kinematic model, 7, and 551
Language:
English
Description:
The Moravia territory has been the subject of geokinematic investigation within scope of several realized research projects and repeated GPS campaigns since 1992. The monitoring has been concentrated on all the Moravia region as well as on particular areas of interest concerning the eventual possible geodynamic changes (Králický Sněžník Massif, Diendorf-Čebín Tectonic Zone (DCTZ) and others). At present time all the territory is covered by several tenths of permanent and epoch GNSS stations. Long observation time series at permanent stations alone are not sufficient for delivering the regional velocity field of sufficient density. On the other hand, epoch stations are more densely spread but periods of repeated observations are less frequent and often the data processing is not homogeneous. In the paper the preliminary kinematic model is briefly described which gives for the first time the general view of movement tendencies at the region of Moravia. On base of long-term monitoring it shows that the Southern Moravia region is more active then it was supposed., Lubomil Pospíšil, Otakar Švábenský and Josef Weigel., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Přírodní hrozby kolem nás - svahové deformace

Creator:
Jana Olivová
Format:
print, bez média, and svazek
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Ústav struktury a mechaniky hornin (Akademie věd ČR), geofyzika, sesuvy půdy, ohrožení životního prostředí, geophysics, landslides, threats to environment, 12, and 00
Language:
Czech
Description:
Jana Olivová.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public