Ionosphere parameters from verticalized oblique ionograms across Italy

• State-of-the-art PRC oblique ionosondes have been developed at INGV using SDR technology. • The IonoNet network provides real-time ionospheric monitoring across Italy through oblique HF soundings. • Oblique ionograms are converted into equivalent vertical ones using geometric verticalization. • Autoscala software retrieves reliable f o F2 and h m F2 parameters from verticalized ionograms. Oblique ionosondes provide an effective means to probe the ionosphere over regions where vertical sounders cannot be deployed, such as oceans or complex terrain. By deploying multiple simple receivers, they also enable a denser spatial sampling of ionospheric conditions. However, extracting ionospheric parameters from oblique ionograms remains challenging due to the long propagation paths and shallow incidence angles of the signals. To address this, verticalization techniques are applied to convert oblique ionograms into equivalent vertical ones, facilitating the retrieval of critical ionospheric parameters. Since 2023, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has developed and deployed new Software Defined Radio (SDR)–based Pseudo Random Code (PRC) oblique ionosondes, establishing the first nodes of the IonoNet network across Italy. The system operates in a multistatic configuration with separated transmitting and receiving sites in northern, central, and southern Italy, enabling the investigation of ionospheric variability over distances of several hundred kilometres. The Autoscala software is used for real-time ionogram scaling and electron density profile derivation, supporting ionospheric monitoring and alerting applications. The network aims to improve regional ionospheric mapping, validate theoretical models, and explore potential lithosphere–ionosphere coupling processes.