An interference suppression method in underwater acoustics based on Riemannian geometry

Array signal processing such as direction of arrival estimation and target localization is significantly impacted by strong interference. In this work, we propose a wideband interference suppression method based on the Riemannian geometry of the manifold of Hermitian positive definite matrices, specifically designed for use in passive sonar systems. We demonstrate that incorporating the Riemannian mean of the sample covariance matrix into conventional beamforming techniques results in a spatial spectrum that effectively rejects interference directions. The proposed interference suppression technique enhances the signal-to-interference ratio without requiring prior information, outperforming other competing approaches. Furthermore, the effectiveness of the proposed method is validated through numerical simulations and comparison with experimental data.