Stokes parameters and DOAs estimation of partially polarized sources using a EM vector sensor

Abstract

In this paper, the problem of polarization and direction-of-arrival (DOA) estimation using an electromagnetic (EM) vector sensor is addressed based on the augmented second-order statistics of quaternions. The augmented quaternion model of an EM vector sensor is introduced by employing the augmented second-order statistics of quaternions, which include the information in both the standard covariance and the pseudo-covariance. The fact is revealed that the Stokes parameters of an EM wave can be extracted from an augmented covariance matrix. An augmented quaternion-based approach is proposed for the Stokes parameters and DOA estimation of polarized EM waves. The proposed approach uses only information in three imaginary parts of both the standard covariance and the pseudo-covariance matrix. In theory, it is guaranteed to remove the effect of the additive noise which is uncorrelated between measurement channels. The proposed approach is applicable to both completely polarized and partially polarized EM waves. Simulations are used to verify the performance of the proposed approach.