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1
Content available remote Skanowanie Kopernika
Figurski M., Pazderski E., Nykiel G., Wolak P., Przyborski M.
Geodeta : magazyn geoinformacyjny
|
2017
|
nr 11
8--15
2
Content available remote Erroneous GNSS Strain Rate Patterns and their Application to Investigate the Tectonic Credibility of GNSS Velocities
Araszkiewicz A., Figurski M., Jarosiński M.
Acta Geophysica
|
2016
|
Vol. 64, no. 5
1412--1429
EN
The paper concerns investigation of the credibility of tectonic interpretation of GNSS strain rates. The analysis was focused on stable regions, where the crustal deformations are small and the reliability of GNSS velocities is questionable. We are showing how the unreliable motion of stations affects calculated strains around them. We expressed distribution of local principal strains by a sinusoidal function and used them to investigate the significance of strain distortion. Then we used this method to investigate real motions of GNSS stations. As a test object we used Polish GNSS stations belonging to the ASG-EUPOS network. Station velocities were estimated on the basis of the 4.5 years of observations. The results let us identify stations that disturb the obtained local GNSS strain rate field. After verification and exclusion of some stations, the new GNSS strains show a much greater internal compatibility and also better fit to the directions of lithosphere stresses.
3
Content available remote Investigation of the 16-year and 18-year ZTD Time Series Derived from GPS Data Processing
Bałdysz Z., Nykiel G., Figurski M., Szafranek K., Kroszczyński K.
Acta Geophysica
|
2015
|
Vol. 63, no. 4
1103--1125
EN
The GPS system can play an important role in activities related to the monitoring of climate. Long time series, coherent strategy, and very high quality of tropospheric parameter Zenith Tropospheric Delay (ZTD) estimated on the basis of GPS data analysis allows to investigate its usefulness for climate research as a direct GPS product. This paper presents results of analysis of 16-year time series derived from EUREF Permanent Network (EPN) reprocessing performed by the Military University of Technology. For 58 stations Lomb-Scargle periodograms were performed in order to obtain information about the oscillations in ZTD time series. Seasonal components and linear trend were estimated using Least Square Estimation (LSE) and Mann-Kendall trend test was used to confirm the presence of a linear trend designated by LSE method. In order to verify the impact of the length of time series on trend value, comparison between 16 and 18 years were performed.
4
Content available remote Ionospheric scintillations computation using real-time GPS observations
Nykiel G., Rachoń L., Figurski M.
Artificial Satellites : Journal of Planetary Geodesy
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2014
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Vol. 49, No. 1
43--53
EN
The following paper presents the results of quasi-real-time determination of the values of phase scintillations indices at the period of ionospheric disturbances that occurred as a consequence of the Sun flares observed on March 7 and 9, 2012. Double-frequency observations with 1-second measurement interval from the EPN (EUREF Permanent Network) network sites located at high latitudes were used for the analysis. To determine the phase scintillations it is necessary to apply data filtering in order to separate the trend of low frequencies (e.g. satellite motion) from high frequency oscillations (e.g. scintillations). Elimination of low frequency components of the signal using moving average was proposed in the research. This approach was conditioned by the necessity to apply an optimum method of filtering for quasi-real-time calculations. The scintillation parameters were calculated by means of three different algorithms and the results were compared. Additionally, relations between changes of the parameters and the ROTI index, describing the temporal changes of TEC, and the decrease of positioning accuracy at the analyzed sites were searched.
5
Content available remote Po co projekt ASG+?
Szafranek K., Araszkiewicz A., Figurski M.
Geodeta : magazyn geoinformacyjny
|
2013
|
nr 7
28--34
6
Content available Problem of intraplate velocity determination for geokinematic interpretations
Bogusz J., Figurski M.
Reports on Geodesy
|
2012
|
z. 2/93
35--40
7
System GNSS geodezyjnych pomiarów przemieszczeń konstrukcji budowlanych
Figurski M., Wrona M.
Inżynieria i Budownictwo
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2012
|
R. 68, nr 5
255-258
PL
Przedstawiono wyniki prac Centrum Geomatyki Stosowanej Wojskowej Akademii Technicznej dotyczących możliwości wykorzystania techniki nawigacji satelitarnej GNSS (Globalny System Nawigacji Satelitarnej) w badaniu zmian geometrii wybranych elementów konstrukcji inżynierskich w czasie. Opracowany system będzie wykorzystywany w badaniu wpływu warunków atmosferycznych (wiatr, nasłonecznienie) na stan geometryczny konstrukcji inżynierskich. Przedstawiono wyniki badań laboratoryjnych oraz pomiarów na rzeczywistych obiektach mostowych.
EN
The results of works of the Centre for Applied Geomatics of the Military University of Technology concerning to the possibility of using the satellite navigation techniques GNSS (Global Navigation Satellite System) in the study of changes in the time of geometry of selected elements of engineering structures were presented in the paper. The developed system will be used to study the impact of weather conditions (wind, insolation) at the geometrical state of engineering structures. The results of laboratory tests and measurements on the real bridges were introduced.
8
Content available remote Unmodelled effects in the horizontal velocity field determination: ASG-EUPOS case study
Bogusz J., Figurski M., Kontny B., Grzempowski P.
Artificial Satellites : Journal of Planetary Geodesy
|
2012
|
Vol. 47, No. 2
67--79
EN
Recent space and satellite technologies offer great opportunities to determine crustal movements in the single, global reference frame. The densification of the global network through local area networks leads to increase the resolution of modelled deformations both horizontal and vertical. However, the credibility of the obtained velocity field is limited by several factors associated with unmodelled (or mismodelled) effects at the stage of GNSS data adjustment. Some of them are periodic (the influence of local atmospheric or hydrological impacts), some temporary (natural or anthropogenic seismicity) or related to local influences (snow load or effects associated with the freezing of the ground). This paper presents the usefulness of ASG-EUPOS time series for determination of the regional velocity field. The system has been operating since mid-2008, so the velocities obtained through the processing of 3-year time series are supposed to be reliable. The paper also presents comparison of the velocity determinations to the geological NNR-NUVEL-1A and geodetic APKIM2005 models.
9
Content available remote Results of the application of tropospheric corrections from different troposphere models for precise GPS rapid static positioning
Wielgosz P., Paziewski J., Krankowski A., Kroszczyński K., Figurski M.
Acta Geophysica
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2012
|
Vol. 60, no. 4
1236-1257
EN
In many surveying applications, determination of accurate heights is of significant interest. The delay caused by the neutral atmosphere is one of the main factors limiting the accuracy of GPS positioning and affecting mainly the height coordinate component rather than horizontal ones. Estimation of the zenith total delay is a commonly used technique for accounting for the tropospheric delay in static positioning. However, in the rapid static positioning mode the estimation of the zenith total delay may fail, since for its reliable estimation longer observing sessions are required. In this paper, several troposphere modeling techniques were applied and tested with three processing scenarios: a single baseline solution with various height differences and a multi-baseline solution. In specific, we introduced external zenith total delays obtained from Modified Hopfield troposphere model with standard atmosphere parameters, UNB3m model, COAMPS numerical weather prediction model and zenith total delays interpolated from a reference network solution. The best results were obtained when tropospheric delays derived from the reference network were applied.
10
Content available remote GPS-derived height changes in diurnal and sub-diurnal timescales
Bogusz J., Figurski M.
Acta Geophysica
|
2012
|
Vol. 60, no. 2
295-317
EN
This paper describes the research concerning precise short-time GPS solutions conducted in the Centre of Applied Geomatics, Military University of Technology, Warsaw, Poland. The data from ASG-EUPOS software and EPN (EUREF Permanent Network) standards and models. In this study, the adapted 3-hour observation window is shifted every hour for obtaining hourly geocentric coordinates in ITRF2005 reference frame. The adjusted network consisted of over 130 stations from Poland and the neighbouring countries, the period covered observations collected from June 2008 through June 2010. These two years of observations allowed for examining short-period oscillations which were found to be closely related to the tidal (dynamic) frequencies. The analysis of the residua from the IERS2003 tidal model was performed using the least squares method with the Eterna software. It confirmed the existence of significant (several millimetres) oscillations in the frequencies corresponding to S1, K1 and K2. The paper describes the idea of data processing and analysis, presents the results of vertical (the Up component) oscillations in main tidal frequency bands, and also includes discussion of possible explanation of the existence of short-period oscillations in the GPS precise solutions and the possibility of propagation of short-period oscillations into long-period spurious changes in the daily (standard) GPS solutions.
11
Content available Using author's GNSS RTK measurement system for investigation of displacement parameters of structure
Figurski M., Wrona M., Nykiel G.
Reports on Geodesy
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2011
|
z. 1/90
124-129
EN
For almost two decades scientists from couple of world famous universities have been working on using satellite navigation data to detect deformations and movement parameters of big structures like tall buildings, long bridges or dams. Evaluation of software and hardware solutions dramatically increases spectrum of construction parameters which can be investigate using GNSS technology. This process is changing very dynamically and brings a lots of possibilities for construction specialist who investigates buildings structures. Today many Structural Monitoring Systems includes high-rate GNSS receivers and software able to calculate phase measurements to sub centimeter level. This paper introduce first test of measurement system based on Global Navigation Satellite System technique and Real Time Kinematic method.
12
Content available Centre of applied geomatics: Scientific activities in the frame of EUREF permanent network
Araszkiewicz A., Bogusz J., Figurski M., Szafranek K.
Reports on Geodesy
|
2011
|
z. 2/91
75-80
13
Content available "ASG+": Project for improving Polish Multifunctional Precise Satellite Positioning System
Figurski M., Bogusz J., Bosy J., Kontny B., Krankowski A., Wielgosz P.
Reports on Geodesy
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2011
|
z. 2/91
51-57
14
Content available remote GPS kontra zagłuszanie
Figurski M., Szołucha M., Mielnik P., Gałuszkiewicz M., Wrona M., Szymański P.
Geodeta : magazyn geoinformacyjny
|
2011
|
nr 1
46-51
PL
Wpływ zakłóceń na pomiary GPS. Czasami wykonanie pomiaru GPS jest z niewiadomych przyczyn niemożliwe lub otrzymane wyniki bardzo mocno odbiegają od zakładanych dokładności. Powodów najczęściej doszukujemy się w czynnikach zewnętrznych. Analizując różne przypadki wadliwych pomiarów, można stwierdzić, że najczęstrzą przyczyną problemów są zakłócenia elektromagnetyczne. Oczywiste jest, że nie wszystkie i nie zawsze oddziaływania promieniowania elektromagnetycznego powodują zanik lub degradację częstotliwości nadawanych przez GNSS. Dlatego Zespół Centrum Geomatyki Stosowanej wykonał szereg badań, których efekty zostały opisane w tym artykule. Generalizując, wpływ zewnętrznych pól magnetycznych można podzielić na dwie grupy: tzw. częstotliwości harmonicznych (których oddziaływanie może w określonych warunkach wpływać na odbiór sygnałów GPS) i celowe zakłócenia przy wykorzystaniu dostępnych w handlu urządzeń do eliminowania sygnałów GPS.
EN
Influence of interferences on GPS measurements. Using GPS receivers we come across various problems related to the measurement accuracy. There are cases where the measurement procedures are hard to follow or a measurement is almost impossible and the results are far from being precise/perfect. The reasons of measurement failure might be different, but they are usually caused by the external factors. We may assume that the most possible explanation is the electromagnetic disturbance, but we should also remember that electromagnetic influence is not always the reason of GNSS frequencies fading and degrading. The Centre of Applied Geomatics has done a series of research and the results are described in this article. The influence of external electromagnetic field might be divided into two classes: harmonic frequency (which may, in certain environment, influence the GPS signals) and so called disturbance on purpose (witch is obtained through the use of available disturbance equipment to eliminate GPS signals).
15
Content available Ocena krótkookresowej stabilności punktów sieci ASG-EUPOS
Bogusz J., Figurski M., Kłos A.
Biuletyn Wojskowej Akademii Technicznej
|
2011
|
Vol. 60, nr 4
7-20
PL
Niniejszy artykuł zawiera wyniki badań, których celem jest poszukiwanie krótkookresowych wahań współrzędnych punktów sieci ASG-EUPOS za pomocą transformacji falkowej. Polska Aktywna Sieć Geodezyjna to wielofunkcyjny system precyzyjnego pozycjonowania satelitarnego założony przez Główny Urząd Geodezji i Kartografii w 2008 roku. Opracowanie dotyczy okresu od czerwca 2008 do lipca 2010 roku, sieci składającej się z ponad 130 stacji polskich oraz zagranicznych. Metoda analizy obserwacji GNS opracowana w Centrum Geomatyki Stosowanej Wojskowej Akademii Technicznej (CGS WAT), które jest jednym z 17 centrów analiz EPN (EUREF Permanent Network Local Analysis Centre) działających obecnie w Europie, jest zgodna z oficjalną strategią i modelami stosowanymi w EPN. Jest ona oparta na oprogramowaniu Bernese 5.0, ale różnica w stosunku do rozwiązań EPN leży w rozwiązywaniu obserwacji za pomocą krótkich okien czasowych. W prezentowanych badaniach jednogodzinne wyniki (współrzędne geocentryczne w układzie ITRF 2005) otrzymano z trzygodzinnych okien obserwacyjnych (66% korelacji), co pozwala na interpretacje dotyczące krótkookresowych informacji rezydualnych w sygnale GNS (Global Navigation Satellite System). Zastosowana we wcześniejszych badaniach analiza FFT i metodą najmniejszych kwadratów (pływowa) dały bardzo spójne wyniki i potwierdziły istnienie kilkumilimetrowych oscylacji dobowych i subdobowych. Analiza falkowa ma na celu badanie wiarygodności konkretnych rozwiązań GNS w zakresie zmian amplitudy drgań w czasie. W wyniku tego badania uzyskane zostały zmiany amplitudy drgań w dobowych i subdobowych pasmach częstotliwości. Mogą być one spowodowane przez sztuczne modulacje pobliskich częstotliwości (P1, S1, K1 w dobowym i S2, K2 w półdobowym), ale również można wyraźnie wyróżnić istnienie sygnałów geofizycznych. Ponadto wykonane zostało porównanie transformat otrzymanych z analizy falkowej dla sąsiadujących stacji (trzy pary sieci ASG - EUPOS).
EN
This publication presents the results of research aimed at searching for short-term oscillations of the ASG network sites using wavelet transform. Polish Active Geodetic Network (ASG -EUPOS) is the multifunctional precise satellite positioning system established by the Head Office of Geodesy and Cartography in 2008. The adjusted network consisted of over 130 stations from Poland and abroad incorporated, the period covered observations gathered from June 2008 to July 2010. The method of processing elaborated in the CAG (Centre of Applied Geomatics, Military University of Technology in Warsaw), which is one of the 17 EPN LAC (EUREF Permanent Network Local Analysis Centre) acting now in Europe, established at the end of 2009, is similar with the official one used in EPN. It is based on the Bernese 5.0 software, but the difference to the EPN's solutions lies in the resolution of resulting coordinates. In the presented research, the 1-hour sampling rate with 3-hour windowing (66% of correlation) is applied. This allows us to make the interpretations concerning short period information in GNS (Global Navigation Satellite System) coordinates series. Analyses using FFT and least squares (tidal) gave very coherent results and confirmed several millimetres diurnal and subdiurnal oscillations. Wavelet analysis is aimed at the investigation of credibility of the precise GNS solutions in terms of changes of the amplitude of oscillations in time. As a result of this study, the changes in the amplitude of oscillations at diurnal and sub-diurnal frequency bands were obtained. These could be caused by the artificial modulations of the near-by frequencies (P1, S1, K1 in diurnal and S2, K2 in sub-diurnal), but also some geophysical signals could be clearly distinguished. Additionally, the comparison of CWTs of near stations (three pairs from ASG -EUPOS network) was performed.
16
Content available remote Residual K1 and K2 oscillations in precise GPS solutions: case study
Bogusz J., Figurski M.
Artificial Satellites : Journal of Planetary Geodesy
|
2011
|
Vol. 46, No. 2
75--91
EN
The continuous GPS observations from Polish Ground-Based Augmentation System (ASG-EUPOS) with two different strategies were analysed. Within the first one the adopted 3-hour observation window was shifted every hour to obtain hourly geocentric coordinates for investigation of the short-period oscillations. The second was the daily solution using EPN (EUREF Permanent Network) standards and recommended models. The Eterna 3.4 software was used for determination of the variations in the tidal frequencies. The almost three-year course of data allow for investigation even close tidal frequencies, especially in PSK1 and S2K2 groups. The variations of the Up component in K1 and K2 waves were found to be significant. It turned out that K1 frequency involves the greatest amount of energy reaching even 11 mm for the Up component. Spurious oscillation up to 4 mm and the period of about 1 year in GPS height time series at the selected ASG-EUPOS sites were obtained. Long-period GPS satellite orbit modelling errors could be directly responsible for small periodic biases in station position determinations as well as the repeating geometry of the satellite constellation with respect to the tracking stations. But it is very difficult to distinguish whether it comes from artefacts (transition of K1 ad K2 in long periods) or real effects (local hydrology). Comparison with the geophysical fluid loadings needs further investigations.
17
Content available Combining of GNSS solutions from BERNESE and GAMIT
Araszkiewicz A., Figurski M., Kroszczyński K.
Reports on Geodesy
|
2010
|
z. 1/88
97-103
18
Content available Centre of Applied Geomatics activities in the context of the EUREF Project
Araszkiewicz A., Bogusz J., Figurski M., Kamiński P., Kroszczyński K., Szafranek K.
Reports on Geodesy
|
2010
|
z. 1/88
89-96
19
Content available remote Podzielmy się klockami
Figurski M., Pakuła-Kwiecińska K.
Geodeta : magazyn geoinformacyjny
|
2010
|
nr 4
18-22
20
Content available Przekształcenia zdjęć satelitarnych Meteosat do projekcji modelu COAMPS
Figurski M., Kroszczyński K., Kamiński P.
Biuletyn Wojskowej Akademii Technicznej
|
2010
|
Vol. 59, nr 2
17-26
PL
W artykule przedstawiono wyniki prac związanych z konstrukcją odwzorowań zdjęć satelitarnych MSG (Meteosat Second Generation), zgodnych z projekcjami niehydrostatycznych modeli mezoskalowych typu COAMPS™ (Coupled Ocean/Atmosphere Mesoscale Prediction System) i Weather Research and Forecasting (WRF). System odbioru zdjęć MSG i model COAMPS™ zostały uruchomione i pracują w trybie operacyjnym w Zakładzie Geomatyki Stosowanej Wydziału Inżynierii Lądowej i Geodezji Wojskowej Akademii Technicznej. Celem prowadzonych prac jest umożliwienie automatyzacji analizy danych pochodzących z różnych źródeł w kontekście wpływu zachmurzenia, wilgotności atmosfery na refrakcję i wartość opóźnienia skośnego GPS. Prezentowana praca stanowi część badań związanych z operacyjnym wyznaczaniem opóźnienia skośnego.
EN
The paper presents the results of research concerning constructing projections of MSG (Meteosat Second Generation) satellite images compatible with projections of non-hydrostatic mesoscale models: COAMPS™ (Coupled Ocean/Atmosphere Mesoscale Prediction System) of the Naval Research Laboratory (NRL), and the WRF (Weather Research and Forecasting). The MSG imagery acquisition system and COAMPS™ model run in the operational mode in the Applied Geomatics Section of the Faculty of Civil Engineering and Geodesy, Military University of Technology. The research aim is to develop automated analysis of data originating from various sources for assessment of the impact of cloudiness (humidity) in the atmosphere on refraction and GPS slant delay. This work is a phase of research concerning operational methods of GPS slant delay determination.
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