$\alpha_{31-53}$. The contribution to the total spectrum of the spectral components with signal/noise ratio equal to 5 is more than 40/found the only spectral component with the spectral index like a synchrotron Galactic radiation has. This is $a_{2,2}$ component with the spectral index $\alpha_{19-31}=-2.86\pm 0.15$, $\alpha_{31-53}=-2.92\pm 0.22$.

The different maps correlation analysis gives the mean spectral index estimate in the region $\alpha=-(2.2 \div 2.3)$.

So we may assume the hypothesis the spectral index is constant and its measured variations are caused only by the instrumental noise.

On the basis of the analysis we can conclude for the most significant Galactic spectral components (with the exception of $a_{2,2}$ ) the Galactic radiation model may be assumed to be one-component, with the radiation cased only by an ionized hydrogen. So the $\Delta\alpha$ variations may be taken as zero.

Now we may determine the measured spectrum

$$b_l^m = \left(
 k(53) - k(31) \left( \frac{53}{31.5}\right)^{-2.15}
                         \right)^{-1}
\left(
a_l^m(53\,GHz) - a_l^m(31.5\,GHz)
      \left( \frac{53}{31.5} \right)^{-2.15}
 \right) \, ,$$

where $k(31)=1./1.025724$, $k(53)=1./1.074197$ are the scale coefficients to transform the thermodynamic temperatures to antenna temperatures for 31.5 GHz and 53 GHz, $a_l^m(31.5\,GHz)$, $a_l^m(53\,GHz)$ are multipole coefficients for 31.5 GHz and 53 GHz maps.

Unfortunately, the COBE sensitivity is 