Adaptive source localisation and blind beamforming for underwater acoustic wideband fast frequency-hop signals of unknown hop sequences and unknown arrival angles using a vector-hydrophone

This paper introduces an underwater acoustic source localization and blind interference rejection algorithm for multiple non-cooperative wideband fast frequency-hop (FFH) spread spectrum signals of unknown hop sequences and unknown arrival angles. This algorithm avoids the need to adjust beamforming weights to accommodate frequency variations in the frequency-hopping signals. This novel approach deploys one vector-hydrophone, which is composed of two or three spatially colocated but orthogonally oriented velocity-hydrophones plus an optional colocated pressure-hydrophone. The spatial colocation of all component hydrophones comprising such a vector-hydrophone frees the beamforming weights of any dependence on the signals' hopping frequencies.