Lowell Oblique-Ionogram Autoscaler

ABSTRACT:Oblique-Ionogram (OI) measurements contain valuable information for operational high-frequency radio services that rely on ionospherically reflected signals. The proposed Lowell Oblique-Ionogram Autoscaler, LOIA will automatically extract and identify the echo traces of ionospherically reflected radio signals in digital OI data records. LOIA will be designed to process a variety of both polarization-tagged and -untagged oblique ionograms. It will operate an intelligent system for trace extraction from OI images based on a bio-plausible model of pre-attentive vision. The intelligent vision model will use a signal detector and a long-range analyzer of potential trace elements to determine if they belong to the same trace. Thus extracted traces will be cross-matched with predicted trace shapes for identification. The predicted shapes will be computed using real-time ionospheric specifications available from the Global Ionospheric Radio Observatory (GIRO) and the IRI Real-Time Assimilative Model IRTAM available from the Lowell GIRO Data Center. Once the extracted traces are identified, LOIA will run an iterative model fit for accurate evaluation of the F layer maximum usable frequencies, MUFo and MUFx.BENEFIT:The Lowell Oblique-Ionogram Autoscaler LOIA can become a powerful tool for companies that provide diagnostics and operational support for the optimization of the operation of HF direction finding and Over-the-Horizon Radar services. LOIA will extract and identify in realtime the echo traces contained in digital ionogram images, and provide the midpoint electron density profiles.