Top row: left panel: visibility function for the entire 325 MHz map (blue line) and the 2deg² COSMOS field (orange line). The median rms within the COSMOS field is denoted by the black dashed line. Middle panel: positions of sources detected using blobcat in the 325 MHz map. The blue rectangle denotes the 2deg² COSMOS field, while the dashed circle shows the pointing half-power radius. Right panel: ratio of total fluxes detected in the 325 MHz map and in the Smolčić et al. (2014) map. The mean and the 1σ interval of the ratio are shown as vertical orange lines. Middle row: left panel: peak-over-total flux ratio, S_P/S_T, as a function of the distance to the pointing center (d) for the 325 MHz map. Red dots show the medians of S_P/S_T for different d bins, with 1σ percentiles as error bars. The fitted Bridle & Schwab (1999) is shown by a blue line. The orange points show the skewness for different d bins, while the orange dashed line shows the overall skewness in this dataset. Right panel: total-over-peak flux ratio, S_T/S_P, as a function of the S/N for the 325 MHz map. The red line shows the fit we used to discern resolved sources. Sources above the red envelope were considered resolved. Bottom row: astrometric offsets of the 325 MHz pointing positions to the 3 GHz catalog. Left panel: two-dimensional distribution of offsets. Dashed blue lines indicate the median offset in right ascension and declination, while the blue shaded region shows the 1, 2, and 3σ covariance ellipses. Middle and right panels: their respective right ascension and declination offset histograms with fitted Gaussians.