Ionosphere

Although the ionosphere is usually benign at MeerKAT L-band, Cotton et al. (2018), "The ionosphere at L band: MeerKAT" demonstrated that direction-dependent ionospheric phase perturbations can occasionally produce time-, frequency-, and field-dependent source-position shifts and imaging artefacts not attributable to instrumental effects. Solar activity was at a minimum during the commissioning of MeerKAT but has been increasing since, and we expect that observations, particularly at UHF band, will be affected.

There is further information on how to calibrate these effect detailed in the page Ionospheric Faraday Rotation Corrections.