Direction finding via biquaternion matrix diagonalization with vector-sensors

Direction-of-arrival (DOA) estimation based on the array of three-component electromagnetic vector-sensors is considered within a biquaternion framework. A relationship is established between the biquaternion covariance and the combination of both complex covariance and cross-product. By exploiting this relationship, the DOA estimates can finally be obtained by diagonalizing the biquaternion covariance matrix of the array outputs in a trilinear PARAFAC manner. This method does not require any a priori knowledge on the position of each sensor, and is shown to offer high robustness to colored noise for direction finding of non-linearly polarized signals. Simulations are provided to illustrate the performance of the proposed method.