ARTIST ionogram autoscaling confidence scores: best practices

Ionogram data from the Global Ionospheric Radio Observatory (GIRO), processed with Automatic Real-Time Ionogram Scaler With True Height (ARTIST), is provided with confidence scores to guide users on the reliability of the data set. Here we use manually processed data to assess the extent to which these confidence scores have value and to provide users with guidelines on how best to apply these confidence scores when filtering GIRO data. It is found that the best confidence score for a given ionospheric parameter (foF1, foF2, or hmF2) is not necessarily the highest confidence score, and depends heavily on the parameter in question. In addition to this we demonstrate an 11.4% false negative rate in ARTIST’s scaling of the F1 layer trace, missing nearly 40% of observed F1 traces.