Abstract
In the ocean environment, the minimum variance distortionless response beamformer usually has the problem of signal self-cancellation, that is, the acoustic signal of interest is erroneously suppressed as interference. By exploring the useful information behind the signal self-cancellation phenomenon, a high-precision direction estimation method for underwater acoustic sources is proposed. First, a pseudo spatial power spectrum is obtained by performing unit circle mapping on the beam response in the direction interval. Second, the online calculation process is given for reducing the computational complexity. The computer simulation results show that the proposed algorithm can obtain satisfactory direction estimation accuracy under the conditions of low intensity of acoustic source, strong interference and noise, and less array snapshot data.
Highlights
Underwater acoustic source localization determines the altitude or depth, range, and bearing angle of the underwater target, that is, the three coordinates of the underwater target in the elliptical coordinate system [1]
It is assumed that the linear array consists of 10 omnidirectional hydrophones, and the spacing of adjacent hydrophones is set to half the wavelength of the narrowband acoustic signal
The signal self-cancellation problem is generally considered to be a disadvantage of the MVDR beamformer and is suppressed
Summary
Underwater acoustic source localization determines the altitude or depth, range, and bearing angle of the underwater target, that is, the three coordinates of the underwater target in the elliptical coordinate system [1]. The key to the subspace-based DOA estimation methods is the estimation of the signal subspace (or noise subspace) To achieve this purpose, one can first perform eigendecomposition on the sample covariance matrix, construct the signal subspace with the eigenvectors corresponding to the larger eigenvalues, and form the noise subspace with the eigenvectors corresponding to the smaller eigenvalues. This paper does not take signal self-cancellation as a troublesome thing, but explores the potential information behind the signal self-cancellation phenomenon and uses it to achieve high-precision DOA estimation of underwater acoustic sources. The main contributions of this paper are: (1) Treating the signal self-cancellation problem of the MVDR-based beamformers from a new perspective, that is, for the MVDR-based beamformers, signal self-cancellation is a nuisance, it contains favorable information and can be used for DOA estimation of underwater acoustic sources. (3) DOA estimation performance of the proposed method is analyzed in the underwater acoustic propagation simulation environment, and the performance comparisons with existing DOA methods is completed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
