Expected compact source sensitivity (red) and brightness sensitivity (blue) as a function of imaging resolution for the 122–124 MHz data from observation 798146. The resolution is varied by altering the visibility weightings with robust and tapering settings. The black curve shows the anticipated confusion noise (defined as 1 source per 10 resolution elements). The red cross shows the location of the 6″ resolution imaging parameters we have used (robust = − 0.5, no taper). Only a small dataset was used for this analysis to limit the computational cost.