Vector Cross Product-Based 2D-DOA and Polarization Estimation With “Long” Electric-Dipole Quint

Dipole antenna elements whose physical length L is greater than or equal to one-tenth of the wavelength λ are generally denoted as long dipoles. Such radiators are more useful in practical polarization sensitive arrays (PSAs) for electromagnetic sensing applications because their radiation efficiency is greater than that of short dipole radiators for which L <; λ /10. Thus, research focused on estimating the parameters of unknown electromagnetic sources using long dipoles has attracted considerable attention from numerous researchers in recent years. However, the development of PSAs and algorithms for this purpose remains in its infancy. In this paper, we propose a PSA composed of five spatially non-collocated long dipoles in a centrosymmetric configuration and apply an algorithm based on the vector cross product for estimating the 2-D direction of arrival (2D-DOA) and polarization parameters of unknown electromagnetic sources. First, the time-domain rotational invariance of the received data facilitates the use of the ESPRIT algorithm for estimating the steering vector. Second, the relationships between the entries of the steering vector are employed to obtain highly accurate, albeit cyclically ambiguous estimates of the directional cosines of the x- and y-axes. Then, the coarse 2D-DOA parameter estimation is conducted using the vector cross product algorithm. Finally, the course 2D-DOA parameter estimations are employed as a reference to obtain a set of highly accurate and unambiguous directional cosine estimates from the previously determined set of cyclically ambiguous estimates. The effectiveness of the proposed algorithm is verified by the simulation results.