Parameters estimation for underwater Doppler signal using unscented Kalman filter

Doppler processing techniques can be used to estimate the parameters of line-spectrum acoustic sources of an underwater target with constant velocity. Previous estimation methods are based on observed frequency or phase which describes the time varying Doppler shift. Because of the low-frequency and low-speed characteristics of underwater linespectrum noise source, the Doppler shift is very tiny and can hardly be detected accurately. It is difficult to estimate the parameters by the previous approaches. A method of underwater Doppler signal parameters estimation based on the unscented Kalman filter is presented in this paper. The signal and measurement systems are placed into state-space form, therefore allowing the unknown parameters of the signal model to be estimated. As a result, the accurate estimation of instantaneous frequency can be avoided. Simulation results are presented to demonstrate the feasibility of the proposed method.