Title: Prying eyes on Northern skies: sub-arcsecond imaging at MHz frequencies

Abstract: Low radio frequencies in the MHz regime are not typically associated with high angular resolution. The long metre-scale wavelengths require baselines on the scales of continents to reach sub-arcsecond angular resolution. The strong influence of the ionosphere on such low-frequency signals does not make it easier either. The International LOw Frequency ARray (LOFAR) Telescope offers a dense array with baselines up to ~2000 km, allowing high-fidelity sub-arcsecond angular resolution imaging down to 30 MHz. Recent advances in calibration and data processing strategies are now paving the way to routine sub-arcsecond processing of ILT data. In this talk I will give an overview of these advances and recent results obtained with the ILT, building up to an outlook on sub-arcsecond surveying of the Northern sky.