Joint DOA and Degree-of-Polarization Estimation of Partially-Polarized Signals Using Nested Arrays

A quaternion-based method is developed to estimate direction-of-arrival (DOA) and degree-of-polarization (DOP) of multiple partially polarized (PP) electromagnetic (EM) source signals, based on the data collected by a linear nested cross-dipole sensor array. The basic insight of the new method for DOA estimation is to form a quaternion vector by exploiting the vectorization of horizontal and vertical polarization data correlation matrices to formulate a quaternion version of MUSIC algorithm. Based on the estimation of DOAs, the DOPs of signals are subsequently estimated by using the Stokes vectors. The performance of the presented method is evaluated and compared with that of conventional complex-based methods.