The frequency invariability of the warped modal signal and the warped signal autocorrelation function in shallow water is discussed.A method is proposed for passive source-range estimation based on the frequency invar...The frequency invariability of the warped modal signal and the warped signal autocorrelation function in shallow water is discussed.A method is proposed for passive source-range estimation based on the frequency invariability and warping transform of signal autocorrelation function received by a single hydrophone in a range-independent or weak range-dependent shallow water environment.In the method,a guided source with a known range is employed to provide the crucial and relative invariant scaled features.The experimental data in shallow water with an iso-speed profile and a fluctuated thermocline are used to verify this approach.The relative errors of the source range estimation are basically less than 10%.展开更多
An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transf...An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transform. For an ideal waveguide, there are invariable frequency features both in the frequency spectrum of the warped signal corresponding to modal cut-off frequencies and the warped signal autocorrelation function due to modal interference. These intrinsic frequency features can be used to passive source ranging. So, the approximate rela- tionship between the frequency of warped signal at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging ap- proach. The estimated ranges are in good agreement with the ranges measured by GPS, and the mean relative error of range estimation is less than 10%.展开更多
基金supported by the Program of "One Hundred Talented People" of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant Nos.11174312,10974218 and 11125420)
文摘The frequency invariability of the warped modal signal and the warped signal autocorrelation function in shallow water is discussed.A method is proposed for passive source-range estimation based on the frequency invariability and warping transform of signal autocorrelation function received by a single hydrophone in a range-independent or weak range-dependent shallow water environment.In the method,a guided source with a known range is employed to provide the crucial and relative invariant scaled features.The experimental data in shallow water with an iso-speed profile and a fluctuated thermocline are used to verify this approach.The relative errors of the source range estimation are basically less than 10%.
基金supported by the Program of One Hundred Talented People of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(11174312,10974218,11125420)
文摘An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transform. For an ideal waveguide, there are invariable frequency features both in the frequency spectrum of the warped signal corresponding to modal cut-off frequencies and the warped signal autocorrelation function due to modal interference. These intrinsic frequency features can be used to passive source ranging. So, the approximate rela- tionship between the frequency of warped signal at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging ap- proach. The estimated ranges are in good agreement with the ranges measured by GPS, and the mean relative error of range estimation is less than 10%.
