Special Issues at Low Frequencies:
Ionosphere
Conclusions:
In order to minimize most effects, it is important to
avoid low elevation angles (high latitudes, sunrise and
sunset)
Remaining effects:
Distortion should be corrected by self-cal (but who can self-cal
quiet sun emission ?).
Image shifts should be detected by images correlation, or
observation of stable small source (Noise Storms), and
corrected within less than 1 beamwidth.
For transient bursts (ex. Type II/III/IV/V bursts) in the absence
of Noise Storms, there is no trivial position correction.