Localization of underwater tone noise sources using instantaneous frequency rate estimate

Doppler effect can be used to estimate the movement parameter of an acoustic source. As one of these parameters, the beam moment is the time at closet point of approach, and it corresponds to the position of acoustic source on the moving object. We introduced a new time-frequency rate distribution referred to as L-phase distribution (LPD), which can accurately estimate the instantaneous frequency rate (IFR) of high-order polynomial phase signal (PPS). The iteration procedure is given to realize the discrete-time LPD. After applying the discrete-time LPD to estimate the IFR of Doppler signal caused by relative motion between the moving acoustic source and the measurement hydrophone, the abeam time is obtained according to the minimum of the estimated IFR, and then the positions of the tone noise sources on underwater moving object can be localized. Localization errors were analyzed using simulations, and the sea experiment results showed the validity of the proposed method.