SMOS MIRAS instrument is designed for three operational modes:
Dual-polarization mode, in which all receivers are switched synchronously to either H or V polarization
Full polarimetric mode, in which segments of the array are switched according to a predefined sequence between H and V
Calibration modes, in which measurements of the internal load, the noise diodes, or the so-called "fringe washing function" are determined.
Note that since June 2010, of the two operational modes (dual and full polarization) the full polarization mode has been selected as the default operational mode.