Noise as measured in the Stokes V continuum of the HRT spectral line (in units of mean quiet-Sun intensity). The noise is measured in every dataset of the RSW2 observations and for the three data levels: L2 degraded data (green), restored with the interpolated PSF L2 data (orange), and aberration-corrected L2 data (blue). The box in each plot displays the computed mean of the measured noise over all daily observations.