Comparison between UHF images obtained with different calibrations. The color scale is the same in all panels. Images are not corrected for the primary beam attenuation. (a) SDP continuum pipeline calibration. (b) Direction-independent calibration on the full FoV (see Section 2.4.1). (c) Direction-independent calibration on the extracted and phase-shifted dataset (see Section 2.4.2); red arrow shows the shift from the original to the new phase center. (d) Direction-dependent calibration (see Section 2.4.3); red polygons show the five facets used for the direction-dependent calibration. The main sources discussed in the paper are labeled.