Simulation measurements for a source with input polarization P = 2%. Each panel shows the case of a different input EVPA: 0, 45, 90, and 135°. Top of each panel: measurements of polarization for each of the simulated frames with their 1σ uncertainties. Bottom of each panel: EVPA measurements for each of the simulated frames with their 1σ uncertainties, together with the measured EVPA and 1σ uncertainty of the polarized sky for comparison. We note that the last exposure could not be measured in two out of the four simulations (for input EVPAs of 0 and 45 deg). EVPAs are shown interchangeably either in the (−90,90] or [0,180) range for clarity.