Characterizing Ionospheric Variability Over Iran Using 3D Ray‐Tracing and Amateur Radio Observations

Abstract

The ionosphere over Iran remains largely uncharacterized, despite its significant influence on high‐frequency (HF) radio‐wave propagation. In this study, three key ionospheric phenomena—the Large‐Scale Traveling Ionospheric Disturbance (LSTID), the Equatorial Ionization Anomaly (EIA), and the Sporadic‐E (Es) layer—were systematically investigated for the first time using a combination of numerical simulations and ground‐based amateur radio observations. A three‐dimensional ionospheric simulation framework was developed and coupled to the PHaRLAP ray‐tracing engine, which numerically integrates the Haselgrove equations to compute HF radio‐wave trajectories and coupled with data from the newly established Ionospheric Monitoring Beacon Receivers (IMBR) network across Iran. The simulation framework incorporated models such as IRI and IGRF to reproduce realistic ionospheric conditions and to analyze the effects of ionospheric phenomena on HF signal propagation. The results demonstrate that each phenomenon uniquely alters radio‐wave paths and signal strength: LSTIDs induce path deviations dependent on disturbance amplitude and direction, EIA affects propagation primarily over southern latitudes through seasonal and diurnal variability, and Es layers cause frequency‐dependent reflection and signal enhancement at HF bands. Initial IMBR observations show good agreement with simulated EIA behavior, while Es events highlight the need for additional data and potential machine‐learning approaches for improved modeling. Overall, this study provides an initial analysis of ionospheric variability over Iran using amateur radio infrastructure and advanced ray‐tracing simulations, establishing a framework for future space‐weather monitoring and HF communication research in the region.