2D DOA estimator for coherently distributed sources using one snapshot

A two-dimensional (2D) direction-of-arrival (DOA) estimation method for coherently distributed (CD) sources has been proposed in high real-time situation using only one snapshot. Utilising two uniform linear arrays (ULAs), the proposed algorithm first construct four equivalent matrices with rotational structures using one snapshot, and then a total equivalent covariance is extended by the four matrices. Finally, two rotational invariance matrices can been calculated by ESPRIT-like algorithm, and the eigenvalues which contains of the information of the central DOAs can be obtained by eigen-decomposition of the two matrices. To improve the performance of the proposed method, in-phased accomplished data is proposed. Without snapshots accumulation, peak searching, and correlation process, the 2D DOA estimation method for CD sources can be used for real-time situation. Several simulation results are used to illustrate the performance of the proposed method.