Exploring Earth’s ionosphere and its effect on low radio frequency observation with the uGMRT and the SKA

The Earth's ionosphere introduces systematic effects that limit the performance of a radio interferometer at low frequencies ($\lesssim 1$\,GHz). These become more pronounced for severe geomagnetic activities or observations involving longer baselines interferometer. uGMRT, pathfinder Square Kilometre Array (SKA), is located in between northern crest Equatorial Ionisation Anomaly (EIA) and magnetic equator. Hence, this telescope prone to ionospheric conditions unique studying ionosphere. Here, we present 235\,MHz with GMRT, showing significant over solar minimum. In work, have characterised disturbances observed GMRT compared them studies other telescopes like VLA, MWA LOFAR situated different latitudes. We estimated total electron content (TEC) gradient full array which shows an order magnitude higher sensitivity Global Navigation Satellite System (GNSS). Furthermore, article uses characteristics from forecast on low-frequency SKA1-MID SKA1-LOW future.