Efficient Method of Passive Localization for Near-Field Noncircular Sources

In this letter, a novel near-field localization algorithm for noncircular sources is proposed using the uniform linear array (ULA). Firstly, an extended covariance matrix is constructed and decomposed to generate the corresponding extended signal subspace and noise subspace. Then, based on the symmetric property of the extended array manifold, the direction-of-arrival (DOA) estimates are obtained via generalized ESPRIT. Finally, the range spectrum function is derived, and the range parameters are consequently estimated through one-dimensional (1-D) search. The proposed algorithm is efficient in that it only requires second-order statistics (SOS) and 1-D spectral search. In addition, compared with the conventional SOS-based methods, the proposed algorithm can improve the estimation accuracy and resolve more sources. Simulation results are presented to validate the performance of the proposed algorithm.