A robust direction of arrival estimation algorithm of coherent wideband sources in unknown correlated noise fields

A robust Direction of Arrival (DOA) estimation algorithm for coherent wideband sources in unknown correlated noise fields is investigated in this paper. In practical applications, the additive noise is usually unknown and correlated among sensors, especially for arrays with comparatively small apertures. The spatially correlated noise incurs an increase in focusing error and a severe degradation in the DOA estimation. To deal with the problem, a new method of focusing transformation based on differentiating covariance matrix is proposed to eliminate noise, and hence reduce the focusing error. The simulation and experiment are carried out to demonstrate that the robustness and resolution are significantly improved at low SNR levels.