Observation of the evolution of the 25th solar cycle by measuring the ionospheric delay using the GPS P3 method in southeastern BrazilGPS P3 method in southeastern Brazil

Authors

  • Fábio Yamada Brazilian Air Force
  • Luiz V. G. Tarelho National Institute of Metrology, Quality, and Technology – INMETRO, Duque de Caxias, RJ, Brazil
  • Mauro V. Lima National Institute of Metrology, Quality, and Technology – INMETRO, Duque de Caxias, RJ, Brazil

DOI:

https://doi.org/10.21014/actaimeko.v14i2.1969

Keywords:

GPS P3 method, ionosphere, ionospheric refraction, total electron content, TEC

Abstract

Ionospheric refraction generates time delay and signal fading in the electromagnetic signals, which can cause errors in the receiver. These errors can range from a few meters in location to total signal unavailability, depending on the ionisation level of the ionosphere plasma. The parameter to evaluate the behaviour of the ionosphere is the Total Electron Content (TEC). This article will present the relationship between the evolution of the number of sunspots of the 25th solar cycle and the Vertical TEC (VTEC) measurement made by a geodetic receiver in the city of Xerém (Brazil). We applied the GPS P3 method of time and frequency transfer to the observables of the receiver. Periods related to the year's seasons (summer and winter) were analysed since the beginning of the 25th solar cycle in 2019. The VTEC analysis characterises the behaviour of the ionosphere caused by the daily, annual, summer, and winter variations in the incidence of solar radiation in southeastern Brazil. Therefore, the analysis can correlate the ionospheric fluctuation with the number of monthly sunspots, referring to the evolution of the 25th solar cycle. The findings of this study are expected to contribute to further developments of a deeper understanding of the ionosphere’s dynamics and further advancements in GNSS-related services.

Downloads

Published

2025-06-26

Issue

Vol. 14 No. 2 (2025)

Section

Research Papers

License

Copyright (c) 2025 Fábio Yamada, Luiz V. G. Tarelho, Mauro V. Lima

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under the CC BY 4.0, Creative Commons Attribution 4.0 International License.

Users are free to

  • share, i.e. copy and redistribute the material in any medium or format for any purpose, even commercially;
  • adapt, i.e. remix, transform, and build upon the material for any purpose, even commercially.

At the same time, the user must give appropriate credit, provide a link to the license, and indicate if changes were made.
Additional information about the license can be found at: https://creativecommons.org/licenses/by/4.0/.

Authors are

  • able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
  • permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).