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Time-frequency analysis of differences between coordinates of three permanent GNSS stations in Krakow

Kosek Wiesław, Siejka Zbigniew

Reports on Geodesy and Geoinformatics

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2023

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Vol. 116

61--68

EN

This paper applies time-frequency analysis to a 3-day time series with a sampling interval of 1 second of the changes in E, N and H coordinates of three permanent GNSS stations: WRON, KR10, and KRUR in Krakow, as well as differences between them. Time-frequency analysis was conducted using a Fourier transform band-pass filter, which separates time series into frequency components. By analyzing the differences between these coordinates, it was observed that the WRON station shows a systematic error in the form of a regular wideband oscillation with a period of 75 minutes, whose amplitude varies from approximately 1 to 3 mm with a period of about 1 day. In the horizontal plane, this oscillation takes the shape of a flattened ellipse with a semi-major axis oriented in the northwest direction. The most probable cause of this regular oscillation is the day-to-day variability of the multipath signal environment.

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Przyczyny zmian ziemskiego klimatu

Kosek Wiesław

Przegląd Geodezyjny

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2020

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R. 92, nr 3

8--12

PL

Obserwowany od ponad stu lat globalny wzrost temperatury na Ziemi powoduje zmniejszanie grubości pokryw lodowych monitorowany za pomocą satelitarnych misji altimetrycznych i grawimetrycznych, a także globalny wzrost poziomu oceanu światowego monitorowany za pomocą pomiarów mareograficznych oraz altimetrii satelitarnej. Jako jedną z przyczyn wzrostu tej temperatury wymienia się działalność człowieka, która związana jest z produkcją gazów cieplarnianych, w szczególności dwutlenku węgla, na skutek spalania olejów napędowych, węgla oraz gazu. Atmosferę ziemską dogrzewa, jednak bez wzrostu globalnej temperatury, stały dopływ energii płynącej z wnętrza Ziemi na skutek rozpadu radioaktywnych izotopów uranu, toru i potasu. Ostatnie badania wskazują, że jedną z przyczyn zmian ziemskiego klimatu może być również zmienna aktywność cyklu słonecznego, która poprzez emisję wiatru słonecznego wpływa na intensywność galaktycznego promieniowania kosmicznego odpowiedzialnego za jonizację troposfery i powstawanie chmur na niskich wysokościach. Nieznaczne zmniejszanie się globalnego zachmurzenia w poprzednim i obecnym stuleciu wpływa na zmniejszanie się średniego albedo, które zwiększa dopływ do powierzchni Ziemi promieniowania słonecznego ogrzewającego troposferę oraz wody oceanu światowego.

EN

The global increase in temperature on Earth, observed for over a hundred years, causes a decrease in the thickness of ice covers monitored by satellite altimetry and gravimetric missions, as well as a global sea level rise monitored by mareographic measurements and satellite altimetry. One of the reasons for the increase in this temperature is human activity, which is associated with the production of greenhouse gases, in particular, carbon dioxide, due to the combustion of fuel, coal and gas. The Earth's atmosphere is warming up, however, without increasing global temperature, by a constant supply of energy flowing from the Earth's interior due to the decay of radioactive isotopes of uranium, thorium and potassium. Recent studies indicate that one of the causes of changes in the Earth's climate may also be the solar cycle variability, which through the emission of solar wind affects the intensity of galactic cosmic radiation responsible for the ionization of the troposphere and the formation of clouds at low altitudes. A slight decrease in global cloud cover in the previous and present century causes the decrease of the Earth's albedo, which increases the inflow of solar radiation to the Earth's surface heating the troposphere and the global sea waters.

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Comparison of Amplitude Variations of Seasonal and Sub-Seasonal Oscillations in Length of Day and Total Solar Irradiance

Kosek Wiesław, Gabryszuk Justyna

Journal of Ecological Engineering

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2020

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Vol. 21, nr 7

52--57

EN

The aim of the study was to identify and compute oscillations in two different time series with similar amplitude variations using length of day data with tide model removed (LODR) and total solar irradiance (TSI) data. The combination of the Fourier transform band pass filter and Hilbert transform allows detecting amplitude variations as a function of the oscillation period. The amplitude variations in two different time series enable computation of frequency dependent or time-frequency correlation coefficients between them. It allows also identifying such oscillations in two time series which have similar amplitude variations. The method applied to LODR and TSI data, enable to detect a possible relationship between them. This comparison method can be applied to any time series which consist of oscillations with non-constant amplitudes.

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Geodesy: General theory and methodology 2015–2018

Borkowski Andrzej, Kosek Wiesław, Ligas Marcin

Geodesy and Cartography

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2019

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Vol. 68, no. 1

145--162

EN

The summary of research activities concerning general theory and methodology performed in Poland in the period of 2015–2018 is presented as a national report for the 27th IUGG (International Union of Geodesy and Geophysics) General Assembly. It contains the results of research on new or improved methods and variants of robust parameter estimation and their application, especially to control network analysis. Reliability analysis of the observation system and an integrated adjustment approach are also given. The identifiability (ID) index as a new measure for minimal detectable bias (MDB) in the observation system of a network, has been introduced. A new method of covariance function parameter estimation in the least squares collocation has been developed. The robustified version of the Shift-Msplit estimation, termed as Shift-M*split estimation, which enables estimation of parameter differences (robustly), without the need of prior estimation of the parameters, has been introduced. Results on the analysis of geodetic time series, particularly Earth orientation parameter time series, geocenter time series, permanent station coordinates and sea level variation time series are also provided in this review paper. The entire bibliography of related works is provided in the references.