Angular power spectra $D_{\ell }^{\text{TT}},D_{\ell }^{\text{EE}},\text{\hspace{0.17em}and\hspace{0.17em}}{D}_{\ell }^{\text{BB}}$ of: (1) scattered light at 30 GHz, 100 GHz, and 353 GHz, with red lines; (2) primordial scalar mode CMB and primordial tensor mode CMB with tensor-scalar-ratio r = 0.001 and r = 0.0001, with black lines; (3) synchrotron emission at 100 GHz and 217 GHz, with orange lines; (4) thermal dust emission at 100 GHz and 217 GHz, with blue lines. Top: spectra calculated with Mask1. Bottom: spectra corresponding to Mask2.