Focusing transform based robust azimuth angles estimation for wideband signals

A focusing transform based minimum variance method (FTMV) is proposed for estimating the azimuth angles of wideband signals. The estimation error of Direction of Arrival (DOA) in the traditional Minimum Variance (MV) method during the array direction changing with the ship can be eliminated by focusing the sample covariance matrices in wideband onto a single narrowband, and accumulating the beamformer outputs on azimuth. Then, the azimuth angles of signals can be estimated accurately. Experimental results show that the FTMV method is more efficient and robust than the MV method in this case.