Communications - Scientific Letters of the University of Zilina 2026, 28(3):A73-A82 | DOI: 10.26552/com.C.2026.043

Circular Analysis of Gnss Positioning Error for Short-Term Rapidly Developing Ionospheric Storm Sub-Classification

Lucija Žužić ORCID...^{1, 2, *}, Ivan Heđi ORCID...³, Jonatan Lerga ORCID...^{1, 2}, Renato Filjar ORCID...^{1, 2, 4}

¹ University of Rijeka, Faculty of Engineering, Department of Computer Engineering, Rijeka, Croatia

² University of Rijeka, Center for Artificial Intelligence and Cybersecurity, Rijeka, Croatia

³ Virovitica University of Applied Sciences, ICT Department, Virovitica, Croatia

⁴ Hrvatsko Zagorje Krapina University of Applied Sciences, Department of Transport Logistics, Krapina, Croatia

In the development of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT), short-lived, fast-growing ionospheric storms (lasting up to three days) were assumed to constitute a single, uniform class of space weather events. To challenge this premise, here is presented a circular analysis of single-frequency commercial-grade Global Positioning System (GPS) horizontal positioning errors in the mid-latitude region during four observed storms (one in 2015 and three in 2017), revealing significant heterogeneity. Maximum positioning errors reached 7.495 m in March 2015, but peaked at 4.261 m, 4.387 m, and 3.948 m during storms in May, early September, and late September 2017, respectively. By demonstrating that short-duration, fast-growing storms require subclassification, in this study is offered a new perspective on disturbances.

Keywords: GNSS PNT performance, circular analysis, ionospheric correction model, Location-Based Services (LBS)

Grants and funding:

This work was supported by the European Regional Development Fund - grant no. PK.1.1.13.0083 and the EU - NextGenerationEU project - grant no. uniri-mzi-25-1 implemented through the University of Rijeka.

Conflicts of interest:

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Received: April 29, 2026; Accepted: July 8, 2026; Prepublished online: July 20, 2026; Published: July 24, 2026  Show citation