This paper concerns an analysis of accuracy of estimated parameters ( ω, Λ, Φ) which define the tectonic plate motions. The study is based on the velocities of station positions published by ITRF2000 for (Satellite Laser Ranging) SLR and (Global Positioning System) GPS technique, separately. The Eurasian, North-American, Australian and Pacific plates were analysed. Influence of the number and localization of stations on estimation accuracy of the tectonic plate motions for SLR and GPS technique were analysed. The discrepancies were discussed., Katarzyna Kraszewska and Miłosława Rutkowska., and Obsahuje bibliografické odkazy
The known models of recent vertical movements of the Earth crust surface in the area of Poland were processed in the form of contour line map on the basis of the data of the first and second class geometric state levelling network. Second map done by Wyrzykowski (1985) was based on the results of measurements made in 1871-1882, 1926-1937, 1952-1956 and 1975-1977. The newest results of assignment of recent vertical movements of the Earth surface in the territory of Poland were published by Kowalczyk in 2006. The map of the contemporary vertical movements velocities has been processed using the least squares collocation method on the basis of repeated measurements of state precise levelling, executed mainly in 1974-1982 and 1997-2003. Presently, after about 3 years of satellite observations at about one hundred of permanent GPS stations of the ASG-EUPOS network, a verification of the mentioned models is possible on the basis of independent (satellite) measurements. As the resolution of the stations in Poland is sufficient, the model processed using satellite data was determined for the whole area of Poland and it was confronted with earlier (levelling) models. There are some differences in the analyzed models. A comparison of levelling and satellite mode ls indicates defect of reference distinctly resulting from sea level variability., Bernard Kontny and Janusz Bogusz., and Obsahuje bibliografické odkazy
A collaborative group between Greek, Polish, and Sl ovak colleagues installed a dense network of non-permanent GPS stations and extensometers to monitor active faults in the eastern part of the Gulf of Corinth, central Greece. The network includes eleven GPS stations across the Kaparelli fault and the Asopos rift valley to the east and two TM-71 extensometers that were installed on the Kaparelli fault plane. So far the G PS network has been measured in three campaigns within the last three years with very good accuracies (1-4 mm in the horizontal plane). Although it is early to draw conclusions on the velocity field and on strain patterns it can be noted that, the data from the extensometers demonstrate both fault-normal opening and shear motion. Given that the total offset on the Ka parelli fault is small, and the geological data suggesting a segmented character of this fault, we expect in the near fu ture to differentiate fault slip and strain accumulation among segments., Athanassios Ganas, Jaroslaw Bosy, Lubomir Petro, George Drakatos, Bernard Kontny, Marian Stercz, Nikolaos S. Melis, Stefan Cacon and Anastasia Kiratzi., and Obsahuje bibliografické odkazy
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
Determination of heights with help of GPS in local geodetic networks is still more actual respecting the fact that the GPS technology becames more and more effective with hardware progress, with improvements in measuring and evaluating procedures, and with better modelling of the disturbing influences. In comparison with GPS the employment of classical terrestrial measuring technologies is often more difficult namely in broken mountain environment. In period 1998-2005 authors carried out repeated measurements of GPS baselines of various length and various height differences in local geodynamical network Sněžník and in other experimental areas. On ground of analyses of large GPS data sets the modified procedure for GPS observation was designed. The procedure is based on repetition of shorter static sessions separated by time intervals of optimal length. This technology represents an alternative to the ususal long static sessions, and is offering better effectivity of vertical GPS measurements with minimal loss of accuracy. The paper presents detailed description of the modified procedure together with some statistical analyses of results. The possibilities of elimination or mitigation of some disturbing influences are discussed. Two testing vertical profiles were marked in Sněžník network- longitudinal profile in N-S direction, and transversal profile in E-W direction - which were measured in course of several years by classical method of very precise levelling, and also by modified GPS heighting procedure in repeated sessions. Results obtained contributed to the local quasigeoid model creation., Otakar Švábenský, Josef Weigel and Radovan Machotka., and Obsahuje bibliografii
GPS (Global Positioning System) technique has become a major tool in contemporary surveying and geodesy. This concerns mostly measurements of horizontal point coordinates, where centimeter-level accuracies are usually required and easily achievable. For the height component, however, these requirements are higher and millimeter-level accuracy is necessary. On the other hand, the intrinsic precision of GPS-derived heights is clearly lower comparing to the horizontal components. This is due to unfavorable satellite geometry, adverse effects of the troposphere or GPS antenna phase center offset and variations. In order to overcome these effects one has to carefully model all the error sources and rigorously process the GPS data. This paper presents studies on the optimal GPS data processing strategy suitable for precise leveling. This was done through the extensive testing and selection of the most appropriate observational session duration, ambiguity resolution strategy, network geometry, troposphere and ionospheric delay reduction methods, signal linear co mbination, elevation angle cut-off, etc. The analyzed processing strategies were evaluated through the processing of a test network. The test network consisted of 19 monitored points and 5 control points, and covered the area of 20 km x 60 km. The obtained results show that the precise GPS leveling with the selected optimal processing strategy allows for about 3 mm repeatability of height measurements when processing 4-hour long sessions. In our opinion GPS leveling may serve as fast and cost-effective replacement of classic geometric leveling, especially in applications where the hei ghts in orthometric or normal height systems are not necessary. This is the case in, e.g., ground deformation studies., Katarzyna Stepniak, Radosław Baryła, Paweł Wielgosz and Grzegorz Kurpinski., and Obsahuje bibliografické odkazy
In Autumn 2010 a new permanent GPS station started observati ons intended to investigate the episodic displacements o f rocks in the Książ Massif, where the Geodynamic Laboratory (LG) is situated. These investigations are being made for common interpretation with water-tubes and horizontal pendulums tiltmeters registering large (one order of magnitude greate r than the tidal effects) non-periodic geodynamic signals. The studies conducted as up to date excluded instrumental and loading effects as potential reasons of those signals. The construction of water-tube tiltmeters and their measuring principles allowed to state that the strong non-tidal signals have a geodynamic nature. To support investig ation of this problem, different analysis of the GPS data are performed in appropriate scales and applying various processing methods. The applied methods refer to selected reference GPS stations in Poland and their neighbors and are aimed at reduction of disturbance effects of geophysical origin such as tectonic activity, post-glacial rebound, anthropogenic effects, etc., Ryszard Zdunek., and Obsahuje bibliografické odkazy
This paper provides a summary of the Geodetic Observatory Pecný achievements within the Centre for the Earth Dynamics Research (CEDR, 2005-2009) project in the field of precise near real-time GNSS analyses. The GOP data centre supporting our own near real-time activities as well as those of various other institutes has been enhanced by including GLONASS data, real-time GNSS data and some other supporting products. The ultra-rapid GNSS orbits are routinely determined and predicte dat GOP by analysing a global network of 60 stations. Significant improvements, which resulted in the fitted and predicted satellite positionrms of 4 and 10 cm, respectively, were achieved within the CEDR project. The GOP orbit product is updated every 6 hours and it routinely contributes to the International GNSS Service (IGS). Based on these predicted precise orbits, the GOP near real-time regiona l GNSS network solution is routinely provided for monitoring water vapour in the atmosphere. Resulting zenith troposphere delays achieved a standard deviation of 3-5 cm compared to precise EUREF post-processing results or a standard deviation of 1-2 mm when converted to precipitable water vapour and compared to a nearby radiosonde. The troposphere delays estimated in GOP are operationally used in the Numerical Weather Prediction., Jan Douša., and Obsahuje bibliografické odkazy
In the paper a problem of elaboration and the use local quasige oid on mining areas in south-eastern Poland is discussed. The models were elaborated within research projects carried by Institution of Geodesy and Cartography AGH in years 1996-2005 and related to mining caused terrain surface deformation problems. One part of the carried research was elaboration of quasi-geoid model that can be used in practical aspects of mine surveying. There is an example of this quasi-geoid model application in leveling surveys presented in the paper. Furthermore, discussed quasi-geoid models elaborated for small areas provide detailed information about the shape of this surface and they determine database completing existing country models as for example Leveling Geoid 2001 for area of Poland., Piotr Banasik., and Obsahuje bibliografické odkazy
The paper presents results of epoch satellite GPS and gravimetric measurements performed on the geodynamic network in central part of the Stołowe Mts. between 1993 and 2009. The research results show significant changes of gravity on most of the points and significant horizontal movement of one point in the central part of the area. The results confirm present day activity of the zone where faults Polický, Bělský and Czerwona Woda Fault Zone exists. In addition, they correspond with the studies of seismic activity in this part of the Sudety Mts., Stefan Cacoń, Jan Kapłon, Bernard Kontny, Josef Weigel, Otakar Švábenský and Jiři Kopecký., and Obsahuje bibliografii