Noise maps per detection patch of MMF3 method measured for a 6′ filter. The noise ranges from 0.5 to 2 times the average noise of the map, which is σ_Y = 2.4 × 10^-4 arcmin². The Ecliptic polar regions, delimited by green contours, with increased redundancy in the observations define a deep survey zone covering in total 2.7% of the sky. It is less noisy than the areas near the Galactic plane, where the dust emission is higher. Two other zones are defined: a medium-deep survey zone of 41.3% coverage delimited by the red contours and with higher noise level; and a shallow-survey zone covering 56% of the sky and with the highest noise levels including regions near the Galactic plane.