Fig. 11
From: Software-defined radio-based HF doppler receiving system
Observations of MSTIDs on 27 November 2020. The top two panels show the Doppler frequency at 5006 kHz obtained with the analog receivers at SGD and SGT. The bottom two panels show the Doppler frequency at 5006 kHz obtained with the digital receivers at CHB and ORI. The grey line in the third panel (CHB–Digital) shows the Doppler frequency obtained with the analog receiver at SGT as shown in the second panel