Comparison of full sky (120° × 120°) Stokes-I residual images created by using 69 sub-bands and 50–300λ baseline cut, and integrating the full observation after DI (first column) and DD calibration (second column) on the NCP (top) and on the RA 18h flanking field (bottom). The DD calibration is performed by SAGECAL with an extensive sky model (~28 000 sources) on the NCP and with a simpler sky model (~3400 sources) on the RA 18h flanking field. The residual power around the centre is substantially lower on the NCP (top right) than the flanking field (bottom right), due to using an extensive sky model with more directions during the DD calibration. The power from Cas A and Cyg A is significantly reduced after DD calibration. The residuals of Cas A are stronger on the NCP (top right) than on the flanking field (bottom right). Unphysical sources below the horizon are masked.