A study ofF₂-layer effects as observed with a Doppler technique

Changes in the height and shape of the ionosphere produce, at a receiver, variations in the frequency of waves emitted from a stable sender. WWV-10, WWV-15, WWV-20 and WWVH-10 have been recorded at Boulder on slow-moving magnetic tape. By rapid playback the Doppler frequency is converted into an audio frequency and the spectrum is analyzed by conventional techniques. Records obtained by this technique are presented to illustrate the phenomena observed during magnetically quiet and disturbed periods. Experimental effects associated with solar flares and magnetic sudden commencements are presented. The frequency dependence of the frequency variations is shown to give information about the height location of the associated ionospheric effects.