Motion parameters estimation of an underwater multitonal source by using field oscillation at different frequencies in deep water

This paper presents a motion parameter estimation algorithm for an underwater multitonal source in deep water. The acoustic field oscillation at different frequency points, caused by the interference between the direct and surface-reflected paths, are utilized to estimate the source initial range, velocity, and depth. The proposed algorithm first estimates the source initial range and velocity by matching the field time series at a reference frequency with the resampled ones at other frequencies. Then, based on the estimated initial range and velocity, the pressure fields in the time domain can be mapped into the sine domain of the receiving angle so that the source depth can be directly obtained by using a modified Fourier transform method on the basis of image theory. The effectiveness of the proposed algorithm is demonstrated via numerical simulations by using the Bellhop acoustic toolbox.