Passive radial velocity and range estimation of a moving source in shallow water

An environmental-,acoustic model-and guided source-independent approach for passive radial velocity and range estimation of a moving source with dual hydrophones in shallow water is proposed.Firstly,the coherent normal modes wavenumber is estimated based on the phase difference of the coherent normal modes obtained by performing distance-wavenumber spectrum(R-K) transform on the low frequency sound filed intensity,then the radial velocity of the moving source is obtained by calibrating the horizontal wavenumber axis.Furthermore,a passive range estimation of the moving source is obtained by performing a WARPING transform on the autocorrelation function of the received signal.For the sound field dominated by the reflected normal modes,the range is estimated using the relationship between the spectral peak frequencies of coherent normal modes after the WARPING transform of the received signal autocorrelation function at a certain two moments and the assumed range.For the sound field dominated by reflected or refracted normal modes,the range is estimated based on the impulse delay of the coherent normal modes after the β-WARPING transform of the received signal at a certain two moments.The noise tolerance analyses are carried out in three hydrological environments such as isovelocity,negative gradient and thermocline sound speed profiles.The results show that the estimation of the range and radial velocity is environmental-independent.The feasibility of the approach is verified by the experimental data at the North Yellow Sea in 2005.The estimated values of radial velocity and source range are in good agreement with the actual values.