censoring is aimed at the improvement of the estimation stability and at the approaching the real data statistic parameters to the used a priori models.

In our case the values on the observed radio map is a sum of a cosmological signal we try to measure, a receiver noise, the Galactic radiation, and perhaps some signal related with neglected systematic effects. It is the cosmological signal that we are interested in, so the other components remain to be carefully estimated, significantly reduced or to be completely excluded. In an ideal case (no Galactic radiation and no systematic effects) the procedure would not cause a significant change in the cosmological signal parameters.

In a Galactic coordinate system one may find a Galactic emission concentrated near the Galactic plane and around the Galaxy center. The radiation may be described using only a few spatial harmonics. If these harmonics are excluded the Galactic radiation is substantially reduced. In our case we excluded 23 harmonics only. At the same time the rest spatial spectrum consist of 649 harmonics. If a signal is normal distributed the 649 harmonics are quite sufficient for a stable signal spectrum parameter estimation.

To estimate the signal parameter adequately it 