Monitoring the Effects of the October 10-11 Solar Storm at Mid-Latitudes Using a GNSS SDR Receiver

The October 10–11, 2024, geomagnetic storm, one of the most intense of solar cycle 25, significantly impacted ionospheric conditions at mid-latitudes. In this study, we analyze the effects of this storm on Global Navigation Satellite System (GNSS) signals using a Software-Defined Radio (SDR)-based receiver at a location in North Italy. The storm, triggered by multiple solar flares and Earth-directed coronal mass ejections (CMEs), induced strong ionospheric disturbances, affecting GNSS signal propagation beyond equatorial and high-latitude regions. To investigate these effects, we recorded GNSS signals on L1 and L2 bands throughout the storm period, along with GNSS observation data from a nearby geodetic station. Our analysis focuses on ionospheric irregularities using the Rate of TEC Index (ROTI) and scintillation indices. ROTI values revealed a significant increase in ionospheric turbulence during the storm’s main phase, coinciding with a Kp index of 9 and a Dst minimum of -335 nT. The recorded IQ samples were processed by using a software receiver, showing moderate amplitude scintillation on multiple GNSS satellites. Furthermore, we show the effectiveness of the Software Defined Radio approach, to capture capture and reconstruct ionospheric disturbances with high fidelity for advanced post-processing of the events. The approach is validated by re-playing the recorded GNSS signals and processing the reproduced scenario by means of a commercial GNSS receiver and successfully reproducing scintillation indices.