The data was treated by SIMuRG \cite{Yasyukevich2020}. For provided GNSS data we acknowledge: Instituto Brasileiro de Geografia e Estatística, Institute of Geodynamics, National Observatory of Athens, Pacific Northwest Geodetic Array (PANGA), Austrian data center (BEV), Système d'Observation du Niveau des Eaux Littorales (SONEL), Dutch Permanent GNSS Array (DPGA), Instituto Tecnológico Agrario de Castilla y León, Korea Astronomy and Space Institute\cite{Dow2009}, The Western Canada Deformation Array (WCDA), REseau NAtional GPS permanent (RENAG), Scripps Orbit and Permanent Array Center, UCSD\cite{Dow2009}, Royal Observatory of Belgium\cite{Bruyninx2012}.

@article{Yasyukevich2020,	
author = {Yasyukevich, Yury and Kiselev, Alexander and Zhivetiev, Ilya and Edemskiy, Ilya and Syrovatskii, Semen and Maletckii, Boris and Vesnin, Artem},	
year = {2020},	
month = {07},	
pages = {},	
title = {SIMuRG: System for Ionosphere Monitoring and Research from GNSS},	
volume = {24},	
journal = {GPS Solutions},	
doi = {10.1007/s10291-020-00983-2}
}

@inbook{Bruyninx2012,
	author = {Bruyninx, Carine and Habrich, H and Kenyeres, Ambrus and SГ¶hne, Wolfgang and Stangl, G. and VГ¶lksen, Christof},
	year = {2012},
	pages = {27-35},
	title = {Enhancement of the EUREF Permanent Network Services and Products},
	volume = {136},
	journal = {IAG Symp.},
	doi = {10.1007/978-3-642-20338-1_4}
}
@article{Dow2009,
	author = {Dow, John and Neilan, R.E. and Rizos, Chris},
	year = {2009},
	pages = {191-198},
	title = {The International GNSS Service in a Changing Landscape of Global Navigation Satellite Systems},
	volume = {83},
	journal = {Journal of Geodesy},
	doi = {10.1007/s00190-008-0300-3}
}