Search

Start Over Language English Subject geodynamika

32. Doris at GOP: from pilot testing campaign to fully operational analysis center

Creator:
Petr Štěpánek, Vratislav Filler, Hugentobler, Urs, and Jan Douša
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, DORIS, DORIS data analysis, IDS, South Atlantic Anomaly, 7, and 551
Language:
English
Description:
a1_In cooperation with AIUB (Astronomical Institute University of Berne), GOP (Geodetic Observatory Pecný) and IGN (Institut Géographique National), DORIS data analysis capabilities were implemented into the development version 5.0 of the Bernese GPS Software. The DORIS observables are reformulated that they are similar to GNSS carrier phase observations as much as possible allowing the use of the same observation models and algorithms as for GNSS carrier phase data analysis with only minor modifications. Evolution of DORIS data analysis using Bernese GPS Software is presented from the pilot campaign (September 2004) to the automatic processing of multi-year data time-series. The station and pole coordinates were estimated within the free-network approach and the long time-series of weekly estimated parameters are presented (1993.0- 2009.0) and analyzed. The RMS of the estimated polar coordinates significantly decreased after 2002, when the second generation of DORIS satellites was launched. A significant improvement has been achieved by processing the data from the new satellites (SPOT-5 and Envisat) launched in 2002. The RMS in 2003-2009.0 shows the decreasing trend and reached values close to 0.4 mas in both coordinates (2007-2008). Behavior of the terrestrial reference frame scale was quite stable with a few exceptions. Analysis of the major scale shift at the end of 2004 revealed the SPOT-5 and Envisat satellites as the source of the problem. On the other hand, the termination of the TOPEX/Poseidon DORIS data processing at the end of 2004 did not influence significantly the overall scale level. Another goal of the paper is a detail analysis of relations between the value of the observation residuals and the length of the observation time-interval. A simple empirical model considering the observation noise as a sum of the constant and time-dependent terms is applied and discussed., a2_A significant DORIS-GNSS ZTD bias as well as station height bias have been detected in the case of the SPOT-5 data for South America stations Santiago, Cachoiera Paulista, and Arequipa. These stations are located in the area of the South Atlantic Anomaly (SAA)., Petr Štěpánek, Vratislav Filler, Urs Hugentobler and Jan Douša., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

33. Earth free oscillations observed in plumb line variations from the 26 December 2004 earthquake

Creator:
Kaczorowski, Marek
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, earth tides, earth free oscillation, plumb line variations, long water-tube tiltmeter, 7, and 551
Language:
English
Description:
The long water-tube tiltmeter observations of the plumb line variations were begun about four years ago. Since 2001, twice, the instrument registered strong plumb line variations associated with earthquake. Earthquake in September 2003 made opportunity for verification of hydrodynamic system of tiltmeter. We obtained in observations large number of cycle-slip effects, which made impossible correct interpretation of data during main phase of phenomenon. Results of tests of dumping system of water waving helped us to introduce some improvements in hydrodynamic system of instrument. Catastrophic earthquake with magnitude 9.1 which took place in the area of Indian Ocean on 26th December 2004 generated phenomenon of the Earth free oscillations associated with anomalous plumb line variations of the order of single milliseconds of arc (mas). The effects of surface waves passing associated with Earth free oscillations were registered by the tiltmeter as series of anomalous plumb line variations. Surface waves produced several milliseconds of arc amplitude of plumb line variations. Results of observations showed that low-pass filters considerably reduce contribution of short-period effects and effectively protect hydrodynamic system of instrument against resonance. Nevertheless during first two hours of phenomenon cycle-slip effects occurred several times. Plot of plumb line variations in space from 26th December 2004 showed us large complication of tilt signals as well as dominated role of tidal signal. Spectral analysis of the time series of the plumb line variations obtained with help of the long water-tube tiltmeter on 26 December 2004 appeared existing fundamental modes (n = 0) in the Earth free oscillations didn’t exceed 0.2 mas., Marek Kaczorowski., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34. Estimates of seasonal signals in GNSS time series and environmental loading models with iterative least-squares estimation (ILSE) approach

Creator:
Kaczmarek, Adrian and Kontny, Bernard
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
geodynamika, geomechanika, geofyzika, geologie, geodynamics, geomechanics, geophysics, geology, wavelet analysis, seasonal signal, coordinates time series, loading models, phase shift, cross-correlation, correlation coefficient, 7, and 551
Language:
English
Description:
The GNSS (Global Navigation Satellite System) coordinates time series are still used as a source for determining the velocities of GNSS permanent stations. These coordinates, apart from the geodynamical signals, also contain an interference signal. This paper shows the results of the comparative analysis of the GNSS coordinates time series with a deformation of the Earth's crust obtained from loading models. In the analysis, coordinates time series are used (CODE Repro2013) without loading models (Atmospheric Pressure Loading, Hydrology, Non-Tidal Ocean Loading) at the stage of the reprocessing of GNSS archival data. The analyses showed that in the case of the Up component there is a high correlation between the GNSS coordinates changes and deformations of the Earth's crust from the loading models (coefficient 0.5-0.8). Additionally, we noticed that for horizontal components (North, East) changes occur in the phase shift between coordinates, and the Earth’s crust deformations signals are accelerated or delayed each other (-150 to 200 days). This article shows new methods of iLSE (iteration Least Square Estimation) to determine periodic signals in the time series. Additionally, we compared the values of estimated amplitudes for GNSS and deformation time series. and Kaczmarek Adrian, Kontny Bernard.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

35. Evaluation of long-term BeiDou/GPS observation quality based on G-Nut/Anubis and initial results

Creator:
Zhao, Lewen, Jan Douša, Václavovič, Pavel, Ye, Shirong, and Xia, Fengyu
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
geodynamika, geomechanika, geofyzika, geologie, otevřený software, jakost, geodynamics, geomechanics, geophysics, geology, open source software, pozorování, G-Nut/Anubis, pre-processing, BeiDou, observation quality, open source, 7, and 551
Language:
English
Description:
Reliable observations are the prerequisite for high-precision GNSS data processing. Data quality evaluation at the pre-processing procedure can help the user to identify the weakness of the observations. The open source software package G-Nut/Anubis developed at Geodetic Observatory Pecny (GOP) is introduced and used for the evaluation of long-term BeiDou/GPS signal. Several key indicators are selected to evaluate the BeiDou/GPS observations. Quantitative analysis shows that more than 100 stations can achieve 6-hour standalone BeiDou positioning at least. The completeness of the BeiDou phase and code observations at three frequencies is higher than that of the GPS observations in the selected station which is mainly attributed to the high elevation observations from GEO and IGSO satellites. Qualitative analysis shows that the multipath effects for pseudorange observations are correlated with signal, receiver types and firmware versions besides the station environment. Users attempting to improve the pseudorange observations by multipath filter should pay attention also to the receiver-specific settings. Cycle slip counts are used to indicate the quality of carrier-phase observations. Results show that BeiDou C05 satellite is more affected by the cycle slips, in particular the third frequency observables. For GPS, the third frequency is more robust compared to the legacy frequencies. Comprehensive single point positioning results show that positioning accuracy for BeiDou is worse than that of GPS, which is mainly caused by less active satellites, worse geometry and the larger errors in the broadcast ephemeris. The BeiDou positioning accuracy was further degraded by the C13/C15 satellite and dominated by large clock errors. Broadcast evaluation shows that the BeiDou orbit errors are related to the constellations. Overall, the orbit precision for both GPS and BeiDou has been gradually improved. Outliers were observed for navigation records assigned with the healthy status, especially for BeiDou broadcast orbits. and Zhao Lewen, Dousa Jan, Vaclavovic Pavel, Ye Shirong, Xia Fengyu.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

36. 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

37. Fracture behaviour of the basalt fibre reinforced composites with polysiloxane-derived matrix

Creator:
Petr Glogar, Černý, Martin, and Tolde, Zdeněk
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, basalt fibre, composite, fracture behaviour, polysiloxane, precursor, 7, and 551
Language:
English
Description:
Selected mechanical properties of unidirectional composites with polysiloxane-derived matrix and continuous basalt fibres reinforcement are presented. A special attention is devoted to the impact of long term exposition in hot air (aimed as a simulation of the anticipated operating conditions) to the composite failure under flexural load. The investigated composites worsened their properties after treatment in air at elevated temperature (650 - 750 °C). The originally non-catastrophic flexural failure changed to a brittle fracture, which was accompanied with a flexural strength decrease. The coalescence of fibres and their strong interaction with the matrix are probably the main reasons for the onset of brittleness. Unless these drawbacks are resolved the service temperature of the composites in air will probably not exceed approximately 500 °C., Petr Glogar, Martin Černý and Zdeněk Tolde., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

38. Geo-kinematics of central and South-East Europe resulting from combination of various regional GPS velocity fields

Creator:
Ján Hefty
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, site velocities, permanent and epoch-wise GPS observations, Euler pole of rotation, regional geo-kinematic, 7, and 551
Language:
English
Description:
The region of Central Europe, Adriatic region and Balkan Peninsula were subjects of geo-kine matical monitoring in several projects performed since 1992. Independent GPS epoch-wise observing campaigns took place in several regions and the whole territory is now covered by tens of permanent stations. The long-term observational series from permanent stations generally yield reliable site velocities, however distribution of such stations is not dense enough to provide velocity field with sufficient resolution all over the monitored region. On the other si de the epoch-wise campaigns sites are much denser than the permanent ones, however the repeated epoch observations are not very frequent and their referencing is not unique. In the paper we shortly describe velo city fields available from various national and regional GPS geo-kinematics projects and an attempt to homogenize the heterogeneous velocity fields is presented. The intraplate GPS velocities in Central and South-East Europe and their reliability are discussed, mainly focusing on Adria and East Balkan region where the geo-kinematics is mostly variable and complicated., Ján Hefty., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

39. Geodetic and geophysical analyses of 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 (navigační systém), gravitace, geodynamika, leveling, gravity, GPS (navigation system), geodynamics, Diendorf fault, Boskovice Furrow, 7, and 551
Language:
English
Description:
In the contribution the results of repeated precise levelling and GPS measurements at the central part of the Diendorf-Čebín tectonic zone (DCTZ) are presented. This morphologically very expressive tectonic system that belongs to a typical type of transcurrent tectonic system, with activity from Protherozoic up to recent period in separate parts is considered to be a seismoactive fault, too. Preliminary results at two measured profiles across central part of eastern marginal fault of the Boskovice Furrow confirmed expected vertical movement tendencies. It is evident that all tectonic system is seismoactive not only in the Lower Austria district but also in its northern continuation., 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

40. Geodynamic effects detected in the Stolowe Góry Mountains investigated originally for gravitational mass movements

Creator:
Cacoń, Stefan, Blahoslav Košťák, and Mąkolski, Krzysztof
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, národní parky, geodetické výpočty, geodynamics, national parks, geodetic networks, recent crust movements, tectonic processes, rock block displacements, table hills, precise levelling, gravity measurements, crack gauging, 7, and 551
Language:
English
Description:
Rock block forms of the Szczeliniec Wielki (919 m a.s.l.) in the border area of the Stolowe Mountains massif originated due to various exogenous and endogenous pro cesses. The processes had started in the Upper Cretaceous, culminated in Late Tertiary, and continue till the present day with much lower intensity. Such processes were indica ted by historical earthquakes and different tectonic events in the Sudeten Mountains and adjacent areas. Results of geodetic geodynamic studies are presented. Several sectors of the Sudeten Mountains which include the Table Hills - Stolowe Mountains, show horizontal and vertical movements. Results of periodic precise levelling in three geodetic micro-networks established on the Szczeliniec Wielki: "Przy Schronisku", "Piekielko" and "Tarasy Poludniowe / Schody" are presented. Investigations have been augmented wit h TM-71 crack gauging in rock blocks. These studies started in 1972 increasing gradually effectiveness of monitoring. Levelling changes, as well as displaceme nts resulting from 3D monthly records of three TM-71 crack gauges have been confronted with recent investigations into tectonic micro-deformations along the Sudeten Fault in the Bohemian Massif. It is suggested that aseismic geotectonic processes participated in the deformations found in investigated networks., Stefan Cacoń, Blahoslav Košťák and Krzysztof Mąkolski., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public