HF Doppler ionospheric monitoring applications: Indications of GNSS positioning accuracy degradation and for LOFAR operations

We present newly established possible applications of HF Continuous Doppler Sounding Systems (CDSS).

Ionospheric hindcasts for purposes of LOw Frequency ARray (LOFAR) telescope are applicable for selecting only suitable LOFAR core measurements for processing. CDSS-based measurements in Belgium, specifically Spread-F intensity and actual Doppler shifts, are evaluated for this purpose.

We demonstrate also statistical relations between GNSS positioning deviations obtained using state-of-the-art Septentrio receivers as well as low-cost U-Blox receivers with wide range of ionospheric condition parameters available for Central Europe, including indicators of Travelling Ionospheric Disturbances developed within the TechTIDE project. The applicable finding is that the ionospheric F-layer Doppler frequency-shift (dF) obtained by CDSS correlates the best from among the analyzed parameters, having positive dF during positive altitude deviations (and vice-versa). We are currently extending the CDSS network, operational in Czechia, Slovakia, Germany and Belgium, as well as in Argentina, South Africa and Taiwan, to other locations of interest. The CDSS can also identify the 3-D parameters of the Medium Scale Travelling Ionospheric Disturbances and infrasound propagating in the ionosphere.