Multi-target localization of underwater acoustic sources based on probabilistic estimation of direction angle

Acoustic signal is one of the most important sensor data for autonomous navigation of underwater vehicles. Underwater vehicles can navigate autonomously by localizing underwater acoustic sources. This paper presents a method of source localization for multiple underwater acoustic sources. The proposed method extracts and identifies target acoustic signals using frequency bands of each source. Then, it utilizes time difference of arrival of two hydrophones to localize the underwater acoustic sources. Using probabilistic direction estimation based on Bayesian process, a reliable directional information can be acquired. The direction angles acquired from various locations of the vehicle are used to perform extended Kalman filter based localization of underwater acoustic sources. The proposed method can provide a reliable estimation of the direction and location of the acoustic source, even under for a noisy acoustic signal. Experimental results verify the performance of the proposed method in a real sea environment.