DOA estimation for coherent sources in the presence of unknown correlated noise

A new direction of arrival (DOA) estimation method is proposed for coherent sources in the presence of spatially unknown correlated noise. The proposed method can fully eliminate the noise component by applying spatial smoothing technique to a new covariance matrix, and the new covariance matrix is the difference between the forward/backward spatial smoothing covariance and its rotation. The unknown correlated noise fields are supposed to be in a complex symmetric Toeplitz form, situations where this assumption is valid is common in sonar applications. Simulation results have shown that the proposed method can fully eliminate noise component and provide significant performance improvement over the conventional forward/backward spatial smoothing algorithm.