Probing equatorial ionosphere using GMRT at sub-GHz frequencies

Radio Interferometer is an array of elements that are simultaneously working together to measure spatial coherence function to provide images of astronomical sources with unmatched resolving power. The effect of the ionosphere limits our ability to explore the sky at sub-GHz frequencies by introducing an extra phase term, which is particularly hard to calibrate in the low signal-to-noise ratio (S/N) regime. Interferometers like Very Large Array (VLA), LOwFrequency ARray (LOFAR), Murchison Widefield Array (MWA), Giant Meterwave Radio Telescope (GMRT), and future instruments such as Square Kilometre Array (SKA) are all affected in the same way.