All NOEMA antennas are equipped with dual polarization receivers. They
measure the signal coming from the pointed direction in two perpendicular
polarizations in the same frequency range. For the current generation of
receiver (2006) and correlators, one or two polarizations are processed by
the correlators, depending on the project settings. We thus have to
introduce the number of polarizations
, which can be set to 1 or 2
and insert it in the radiometer equation with