DOA Estimation of Helicopters Using Acoustic Vector Sensor in Complex Environment

The direction of arrival (DOA) estimation for helicopters is a challenge, which becomes more serious in complex environments with interference. How to estimate the arrival angle correctly from the far-field signal with strong interference and high noise is the key problem. Two points (DOA estimation and eliminating interference) are extracted from the problem and two approaches are provided to solve each of them: (1) An optimized Hankel-singular value decomposition method is proposed in order to release the effect of interference and noise in complex environments; (2) A maximum likelihood estimation (MLE) method is provided in this study based on acoustic vector sensor to solve the estimation problem. DOA estimation with vector sensors performs more flexibly and more accurately than that with scalar sensors. It is shown in the simulation that the proposed method achieves better performance in anti-interference than the traditional MLE method. The DOA estimation results are also accurate enough to show the superiority of the acoustic vector sensor.