This paper substantiates the method of polarization selection of navigation objects located in the zone of atmospheric formations (i.e., precipitation of different intensity and phase state), based on polarization differences
in the parameters of their echo signals in a partially polarized electromagnetic wave arriving at the input of the
all-polarized antenna of the ship radar polarization complex (SRPC). The partially polarized wave is represented as consisting of two polarized streams with polarization degrees m1 and m2 corresponding to the echo signals
of the navigation object and atmospheric formation. The property of the partially polarized electromagnetic
wave reflected from a complex object (i.e., navigation object located in the zone of atmospheric formation) is
represented by real energy polarization Stokes parameters having intensity dimension. The scattering ability
of the complex object is represented by the Mueller scattering matrix, the elements of which are measured by
SRPC when it is sequentially irradiated with electromagnetic waves of four fixed polarizations. Polarization
selection of navigation objects located in the zone of atmospheric formations uses the difference of polarization degrees of echo signals of the navigation object and atmospheric formation. The process of selection of
the navigation object echo signal from the echo signal of the complex object and its observation on the screen
of the SRPC indicator or computer display is based on the relationship between the degree of polarization of
the electromagnetic wave and the polarization parameters of the navigation object echo signal and the atmospheric formation. The aim of this research is to develop polarization criteria of optimality of radar parameters
of echo signals of partially polarized electromagnetic waves, represented by polarization degrees m1 and m2
corresponding to the navigational object and atmospheric formation observed by SRPC. As a result of the performed research, the problem of polarization selection of navigation objects located in the zone of atmospheric
formations along the ship’s trajectory according to the values of the polarization degree of the navigation object
echo signal is solved.