Uncertainty on the unbiased estimation of the B-mode power spectra based on 100 simulations containing E only (left panel), noise only (central panel) and E, B and noise (right panel), see Sect. 6.3.2 for more details. The last case estimates the total uncertainty on the BB power spectrum estimation. The spectra are estimated with help of cross-spectra of simulated pairs of maps. For the explanation of the legend, see Fig. 12. In the case of simulations containing noise we also display the “No filters” case, in which the simulated white noise TOD are not filtered: the simple map-making Eq. (5) is adopted.