BB angular power spectra from S (on the top) and S+N (on the bottom) residual maps for the minimal case of one detector and one operation day. HWP stepped every 60 s with a telescope scanning rate of 12 deg/s (solid black line); HWP stepped every 3600 s with a telescope scanning rate of 0.7 deg/s (dashed black line); HWP spinning at 5 Hz with a telescope scanning rate of 0.7 deg/s (solid red line); HWP spinning at 0.5 Hz with a telescope scanning rate of 12 deg/s (dashed red line). The BB spectrum from the input map is shown for comparison by the green dot-dashed line (in the S case the spectrum is rescaled down by a factor of 10²).