Evaluation of automatic ionogram scaling for use in real-time ionospheric density profile specification: Dourbes DGS-256/ARTIST-4 performance

Statistical evaluation of the Dourbes (4.6 E, 50.1 N) digisonde automatic scaling of the more frequently used ionospheric parameters (foF2, foF1, foE, h’F2, h’F, h’E, and M3000F2) was performed using automatically and manually scaled data from the time period of 2002 to 2008. Automatic scaling was provided in 92% to 94% of cases for most characteristics, except for foF1 (81%). In terms of the automatic scaling accuracy, the magnitude of the residual error for foF2 and M3000F2 (automatically minus manually scaled values) varied according to local time, season, and solar activity. Although geomagnetic storms appear to affect the automatic scaling, the overall results for the influence of geomagnetic activity were inconclusive. Based on this analysis, error bounds were determined (95% probability) for each characteristic: foF2 (–0.75,+0.85), foF1(–0.25,+0.35), foE(–0.35,+0.40), h’F2(–68,+67), h’F(–38,+32), h’E(–26,+2), and M3000F2(–0.55,+0.45).