PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Effect of the GLONASS-specific receiver antenna phase center corrections on the results of european regional GNSS network
100%
Liwosz T.
Artificial Satellites : Journal of Planetary Geodesy
|
2013
|
tom Vol. 48, No. 4
191--203
EN
In the paper I investigated the effect of the GLONASS-specific receiver antenna phase center corrections on the results of a regional permanent GNSS network. I made analysis, using Bernese GPS Software 5.0, of GPS-only and GPS-GLONASS (GNSS) observations collected at permanent sites in Europe. Two types of GNSS solutions were computed: with GPS phase center corrections used for observations of both systems, and with the system specific corrections for observations of the respective system. The Bernese software was modified accordingly to use GLONASS specific corrections for GLONASS measurements. The results, i.e., coordinates and tropospheric zenith delays were analyzed and compared between computed solutions. Introducing GLONASS-specific receiver antenna phase center corrections did not improve the repeatability of the GNSS coordinate time series. Differences of coordinates between the two GNSS solutions were highly repeatable but offsets (biases) were observed; maximum bias for horizontal component was 1 mm and 4 mm for up component. Similar biases were observed for stations with the same antenna models. Periodic signal with a period of 1/3-year was found in difference time series between GPS and GNSS solutions for north component with a maximum peak-to-peak amplitude 2.8 mm. The periodic signal was attributed to GLONASS.
2
Content available Studies of crustal deformation due to hydrological loading on GPS height estimates
63%
Rajner M. , Liwosz T.
|
2011
|
tom Vol. 60, no 2
135-144
EN
The paper deals with large-scale crustal deformation due to hydrological surface loads and its influence on seasonal variation of GPS estimated heights. The research was concentrated on the area of Poland. The deformation caused by continental water storage has been computed on the basis of Water GAP Hydrological Model data by applying convolution of water masses with appropriate Green's function. Obtained site displacements were compared with height changes estimated from GPS observations using the Precise Point Positioning (PPP) method. Long time series of the solutions for 4 stations were used for evaluation of surface loading phenomena. Good agreement both in amplitude and phase was found, however some discrepancies remain which are assigned to single point positioning technique deficiencies. Annual repeatability of water cycle and demanding procedure for computing site displacements for each site, allowed to develop a simple model for Poland which could be applied to remove (or highly reduce) seasonal hydrological signal from time series of GPS solutions.
PL
Celem niniejszej pracy jest analiza wpływu zmian wielkoskalowych stosunków wodnych na deformacje skorupy ziemskiej. Przedstawiona jest również możliwość monitorowania tego efektu przy pomocy geodezyjnych technik satelitarnych. Na podstawie zmiennego rozkładu mas hydrosfery lądowej (do tego celu wykorzystano model hydrologiczny WGHM) oraz wykorzystując informacje dotyczące właściwości skorupy ziemskiej (tzw. funkcje Greena) zostały obliczone modelowe zmiany wysokości wybranych punktów na terenie Polski. Wyniki te zostały porównane ze zmianami wysokości wyznaczonymi dla czterech stacji permanentnych GNSS, które dysponują długimi ciągami obserwacyjnymi, tj. Borowa Góra, Borowiec, Józefosław oraz Lamkówko. Do opracowania obserwacji GPS wykorzystana została metoda Precise Point Positioning (PPP), czyli obserwacje dla każdej stacji były opracowywane niezależnie. Pozwoliło to na odseparowanie sygnałów właściwych dla danej stacji pomiarowej i prawidłowa interpretacje geodynamiczna. Wyniki te dobrze zgadzają się co do amplitudy i fazy z modelowym efektem. Przyczyny widocznych rozbieżności również zostały przedyskutowane. Wyraźna, roczna powtarzalność deformacji wynikających ze zmiennego rozkładu mas wodnych, pozwoliła na skonstruowanie prostego dwuparametrowego modelu dla terenu Polski, który pozwala znacznie zredukować wpływ tego efektu bez konieczności złożonych obliczeń.
3
Content available remote Analysis of integrated water vapourderived using GPS
51%
Kruczyk M. , Rogowski J. , Liwosz T.
|
|
tom z. 2/57
161-167
EN
Various numerical experiments concerning determination of IWV over permanent GPS stations in Central Europe are reported here. We analysed changes of the formula for mean temperature from radiosounding (conducted by Polish Institute of Meteorology and Water Management). Radiosonde and numerical weather model - derived IWV were compared to postprocessed solutions for GPS stations. Different: GPS solutions (both daily and hourly, applying different orbit products), hydrostatic and dry models, real and model assimilated meteo data were compared and analysed.
4
Content available remote On accuracy of IPWV determined from GPS networks
51%
Kruczyk M. , Rogowski J. , Liwosz T.
|
|
tom z. 3/58
139-142
5
Content available Integrated precipitable water from GPS observations and CIMEL sunphotometer measurements at CGO Belsk
51%
Kruczyk M. , Liwosz T. , Pietruczuk A.
|
|
tom Vol. 103
46--65
EN
This paper describes results of integrated precipitable water co-located measurements from two techniques: GPS solution and CIMEL-318 sun-photometer. Integrated Precipitable Water (IPW) is an important meteorological parameter and is derived from GPS tropospheric solutions for GPS station at Central Geophysical Observatory (CGO), Polish Academy of Sciences (PAS), Belsk and compared with sunphotometer (CIMEL-318 device by Cimel Electronique) data provided by Aerosol Robotic Network (AERONET). Two dedicated and independent GPS solutions: network solution in the sub-network of European Permanent Network (EPN) and precise point positioning solution have been made to obtain tropospheric delays. The quality of dedicated tropospheric solutions has been verified by comparison with EPN tropospheric combined product. Several IPW comparisons and analyses revealed systematic difference between techniques (difference RMS is over 1 mm). IPW bias changes with season: annual close to 1 mm IPW (and semi-annual term also present). IPW bias is a function of atmospheric temperature. Probable cause of this systematic deficiency in solar photometry as IPW retrieval technique is a change of optical filter characteristics in CIMEL.
6
Ocena możliwości podniesienia dokładności jednoczęstotliwościowych obserwacji GPS w zastosowaniach geodezyjnych
51%
Figurski M. , Wielgosz P. , Liwosz T.
|
|
tom 17
7
Content available remote Some aspects of GPS tropospheric delay behavior, usefulness and estimation
51%
Kruczyk M. , Liwosz T. , Rogowski J. B.
|
2004
|
tom nr 2/69
235--242
EN
Our paper highlights some different areas of our research in GPS meteorology. We have made many statistical quality analysis of the many standard tropospheric solutions and ZTD combined product (EPN and IGS). This work can be useful for both combined product users and improved processing strategy guidelines. The core of our interest is tropospheric delay estimation and usage in practical activity such as permanent network and epoch campaign adjustment. We report current works leading to start of NRT tropospheric service in WUT LAC. Finally we present some interesting ideas how to use tropospheric delay in meteorology and climatology (e. g. long IPW series for different dimate conditions, IPW distribution maps, correlation of IPW series for different stations and other parameters, comparisons with radiosounding profiles, IPW derivation).
8
Content available remote CERGN 2003 solution and its relation to CERGN 1994-2001 campaign results
45%
Hefty J. , Stangl G. , Cristea E. , Kratochvil R. , Liwosz T.
|
|
tom z. 4/79
359-366
EN
Analysis strategy and results from CEGRN epoch campaign in 2003. Combined product based on individual network solutions by four analysis centres and its comparison with CEGRN 2001 coordinates. Time evolution of coordinates at some long-term observed CEGRN sites during seven epoch campaigns since 1994.
9
Content available remote WUT LAC status report
38%
Bogusz J. , Figurski M. , Kruczyk M. , Kujawa L. , Liwosz T. , Pfeil M. , Rogowski J.
|
|
tom z. 3/58
67-72
10
Content available remote CEGRN 2003 solution and its relation to CEGRN 1994-2001 campaign results
38%
Hefty J. , Gerhátová L. , Stangl G. , Cristea E. , Kratochvíl R. , Liwosz T.
|
|
tom z. 2/73
33-40
EN
Analysis strategy and results from CEGRN epoch campaign in 2003. Combined product based on individual network solutions by four analysis centres and its comparison with CEGRN 2001 coordinates. Time evolution of coordinates at some long-term observed CEGRN sites during seven epoch campaignssince 1994.
11
Content available Determination of the deformation of the Earth's crust in Poland
38%
Bogusz J. , Kujawa L. , Liwosz T. , Rogowski J. B. , Jarosiński M. , Kłęk M.
|
2008
|
tom z. 2/85
19-29
12
Content available remote Research programe of the astrogeodetic observatory in Józesław
32%
Rogowski J. B. , Bogusz J. , Figurski M. , Kłęk M. , Kruczyk M. , Kujawa L. , Kurka W. , Liwosz T.
|
2004
|
tom nr 2/69
213--233
EN
Astrogedodetic Observatory Józefoslaw was joined to the IGS in 1991 and started to the permanent service in 1993. To day GPS stations JOZE and JOZE working in the frame IGS/EUREF. JOZ2 station participate in IGLOS an EUREF IP pilot projects. Results of tidal gravimetric observations; absolute gravity measurements; changes of the vertical, based on the gravimetric measurements and astrometric observations; hydrological and meteorological observations are the base for study of local deformations model. The results of practical test of RTK and DGPS measurements using mobile phone for data transmission performed since 1998 are also presented in the paper. WUT EUREF Local Analysis Centre, one of the 16 Local Analysis Centres acting in Europe, is a very important part of the Observatory. The Centre makes continuous service of one-week solution in the frame of EUREF network, processes national and international GPS campaigns, models ionosphere and troposphere parameters. The part of this Centre is automatic service for GPS data processing. The results of mentioned above work are presented in the paper.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.