Correlation between ICA CMB and simulated CMB in Ka (plus sign =p, square =g, ‘x’=t) and Q band (asterisk =p, diamond =g, triangle =t) towards recovered frequency scaling at 30, 40 and 60 arcmin. Dot–dashed lines show the expected scaling (1.022). Dotted lines indicate the minimum correlation and the maximum scaling for a good CMB reconstruction. We can also observe that correlation with CMB-Q map is greater than with CMB–Ka map.