Polarization estimation with a dipole-dipole pair, a dipole-loop pair, or a loop-loop pair of various orientations

This work aims to estimate the polarization of fully polarized sources, given prior knowledge of the incident sources' azimuth-elevation directions-of-arrival, using a pair of diversely polarized antennas-two electrically small dipoles, or two small loops, or one each. The pair may be collocated, or spatially separated by a known displacement. Each antenna may orient along any Cartesian coordinate. Altogether, 15 antenna/orientation configurations are thus possible. For each configuration, this paper derives 1) the closed-form polarization-estimation formulas, 2) the associated Cramér-Rao bounds, and 3) the associated computational numerical stability.