Influence of background-noise spatial coherence on high-resolution passive method
New signal processing methods for passive listening have appeared recently : they are called "high resolution" methods because they have theoretically a better resolving power than conventional or adaptive beamforming . But they need additional knowled ge on background noise structure, and particularly on ambient noise for low frequency. These methods are based on the estimation of the spectral density matrix of the signal received on the array and on the utilization of its eigenvectors and eigenvalues. This matrix contains the background noise spectral density matrix for which a good parametrized model is needed. Performances estimated by simulations show on one hand the interest of high resolution methods compared to conventional methods, and on the other hand their sensitivity to the background noise model which is used.
SourceIn: Underwater Ambient Noise (SACLANTCEN Conference Proceedings CP-32), Vol. 2, Part 2, 1982, pp.