2D DOA Estimator for Multiple Coherently Distributed Sources Using Modified Propagator

In this paper, we propose a new algorithm for estimating the two-dimensional (2D) nominal direction-of-arrivals (DOAs) of multiple coherently distributed (CD) sources by utilizing three parallel uniform linear arrays (ULAs). The proposed algorithm firstly shows that some rotational eigenstructures exist approximately for three pair of shifted ULAs. And then a modified propagator method is used to estimate three rotational invariance matrices which denote the rotational eigenstructures. Finally, the nominal angular parameters of CD sources are obtained from the eigenvalues of the rotational invariance matrices. Without spectrum searching, the estimation and eigendecomposition of the sample covariance matrix, our approach is computationally more attractive compared with the earlier algorithms. In addition, it can be applied to the scenario with multiple sources that may have different angular distribution shapes. Simulation results illustrate the performance of the algorithm.