Multiple real-time 3D tracking of simultaneous clicking whales using hydrophone array and linear sound speed profile

This paper provides a real-time passive underwater acoustic method to track multiple emitting whales using four or more omni-directional widely-spaced bottom-mounted hydrophones. After a non-parametric Teager-Kaiser-Mallat signal filtering, rough time delays of arrival are calculated, selected and filtered, and used to estimate the positions of whales for a constant or linear sound speed profile. The complete algorithm is tested on real data from the NUWC¹ and the AUTEC². Our model is validated by similar results from the US Navy and Hawaii Univ labs in the case of one whale, and by similar whales counting from the Columbia univ. ROSA lab in the case of multiple whales. At this time, our tracking method is the only one giving typical speed and depth estimations for multiple (5) emitting whales located at 1 to 5 km from the hydrophones.