Weighted Histogram Method for DOA Estimation Using Single Vector Hydrophone

Using vector hydrophone for direction of arrival(DOA) estimation in unmanned undersea system is advantageous, and this can be realized by the weighted histogram method with less computation using single vector hydrophone. In this study, the principle of acoustic energy flux detector is analyzed, the distribution of acoustic energy in the plane can be obtained from acoustic energy flux, which provides the theoretical basis for the weighted histogram method. It is observed that the energy of the sound source extends beyond the real orientation under low signal-to-noise ratio(SNR) through the analysis. Hence, the statistical interval of the weighted histogram method will segment the energy of the sound source and a DOA estimation error will occur. Aiming to the problem existing in the previous algorithm, an improved weighted histogram method based on energy search is proposed. In the new algorithm, the slide window method is used to find the range of sound source, and the center of gravity method is used to obtain the energy center which is the DOA estimation result. The simulation results show that the algorithm has better performance when the statistical interval is 10° and the SNR is within the range of 10 dB to 10 dB. Its root mean square error is 43.7% less than that of the previous algorithm and its DOA estimation results are comparatively accurate in a multi-target(interference) environment. The research in this paper provides a reference for improving the algorithm of DOA estimation using single vector hydrophone.