Em. Warrington, OBSERVATIONS OF THE DIRECTIONAL CHARACTERISTICS OF IONOSPHERICALLY PROPAGATED HF RADIO CHANNEL SOUNDING SIGNALS OVER 2 HIGH-LATITUDE PATHS, IEE proceedings. Microwaves, antennas and propagation, 145(5), 1998, pp. 379-385
The author presents measurements of the directional characteristics of
the Doppler and time delay components of a pulsed channel sounding si
gnal received over two high latitude paths. A variation in bearing wit
h Doppler frequency was frequently evident, an effect attributed to Do
ppler shifts imposed on the signal when scattered from ionospheric irr
egularities drifting across the reflection points. For a transauroral
path, for which the ionospheric reflection points were subauroral, sta
ndard deviations of up to similar to 2.5 degrees were observed in the
azimuthal power distribution of the received energy. Much greater dist
urbances with azimuthal standard deviations of up to similar to 35 deg
rees were recorded on signals received over a path contained entirely
within the polar cap path.