The horizontal-longitudinal correlations of the acoustic field in deep water are investigated based on the experi- mental data obtained in the South China Sea. It is shown that the horizontal-longitudinal correlation ...The horizontal-longitudinal correlations of the acoustic field in deep water are investigated based on the experi- mental data obtained in the South China Sea. It is shown that the horizontal-longitudinal correlation coefficients in the convergence zone are high, and the correlation length is consistent with the convergence zone width, which depends on the receiver depth and range. The horizontal-longitudinal correlation coefficients in the convergence zone also have a division structure for the deeper receiver. The signals from the second part of the convergence zone are still correlated with the reference signal in the first part. The horizontal-longitudinal correlation coeffi- cients in the shadow zone are lower than that in the convergence zone, and the correlation length in the shadow zone is also much shorter than that in the convergence zone. The numerical simulation results by using the normal modes theory are qualitatively consistent with the experimental results.展开更多
The horizontal-longitudinal correlation of acoustic field for the receiver near the bottom is analyzed by using nu-merical modeling.An approximate analytical solution of horizontal-longitudinal correlation coefficient...The horizontal-longitudinal correlation of acoustic field for the receiver near the bottom is analyzed by using nu-merical modeling.An approximate analytical solution of horizontal-longitudinal correlation coefficient is derived based on the ray method.Combining the characteristic of Lloyd's mirror interference pattern,the variability of acoustic field and its effect on horizontal-longitudinal spatial correlation are discussed.The theoretical pre-diction agrees well with the numerical results.Experimental results confirm the validity of analytical solution.Finally,the applicability of the analytical solution is summarized.The conclusion is beneficial for the design of bottom-moored array and the estimation of integral time for moving source localization.展开更多
The horizontal-longitudinal correlation of the sound field decreases rapidly in the shadow zone of the deep sea,which severely limits the detection performance of the horizontal array in this area.This paper employs a...The horizontal-longitudinal correlation of the sound field decreases rapidly in the shadow zone of the deep sea,which severely limits the detection performance of the horizontal array in this area.This paper employs a range-frequency interference structure to frequency-shift compensate the acoustic field at different longitudinal intervals to improve the horizontal-longitudinal correlation of the acoustic field in the shadow zone.Firstly,the range-frequency interference structure and the horizontal-longitudinal correlation are analyzed by simulation based on a deep-sea experimental environment,and the simulated horizontal-longitudinal correlation of the acoustic field is improved through frequency-shift compensation by using an equivalent waveguide invariant.Then the experimental acoustic data from the deep-sea experiment is analyzed.The horizontal-longitudinal correlation of the received acoustic field in the first shadow zone at three depths and two ranges is processed.The data processing results show that the horizontal-longitudinal correlation length after frequency-shift compensation is increased by approximately 4 to 11 times compared to before the frequency-shift compensation.The simulated and experimental results demonstrate that the use of a range-frequency interference structure for frequency-shift compensation of the received acoustic field can effectively improve the horizontal-longitudinal correlation of the sound field in the shadow zone of the deep sea.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11434012 and 11174312
文摘The horizontal-longitudinal correlations of the acoustic field in deep water are investigated based on the experi- mental data obtained in the South China Sea. It is shown that the horizontal-longitudinal correlation coefficients in the convergence zone are high, and the correlation length is consistent with the convergence zone width, which depends on the receiver depth and range. The horizontal-longitudinal correlation coefficients in the convergence zone also have a division structure for the deeper receiver. The signals from the second part of the convergence zone are still correlated with the reference signal in the first part. The horizontal-longitudinal correlation coeffi- cients in the shadow zone are lower than that in the convergence zone, and the correlation length in the shadow zone is also much shorter than that in the convergence zone. The numerical simulation results by using the normal modes theory are qualitatively consistent with the experimental results.
基金Supported by the National Natural Science Foundation of China under Grant No 11174235
文摘The horizontal-longitudinal correlation of acoustic field for the receiver near the bottom is analyzed by using nu-merical modeling.An approximate analytical solution of horizontal-longitudinal correlation coefficient is derived based on the ray method.Combining the characteristic of Lloyd's mirror interference pattern,the variability of acoustic field and its effect on horizontal-longitudinal spatial correlation are discussed.The theoretical pre-diction agrees well with the numerical results.Experimental results confirm the validity of analytical solution.Finally,the applicability of the analytical solution is summarized.The conclusion is beneficial for the design of bottom-moored array and the estimation of integral time for moving source localization.
基金supported by the Goal-Oriented Project Independently Deployed by Institute of Acoustics,Chinese Academy of Sciences(MBDX202101)the Hainan Provincial Natural Science Foundation of China(123MS105)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0700100).
文摘The horizontal-longitudinal correlation of the sound field decreases rapidly in the shadow zone of the deep sea,which severely limits the detection performance of the horizontal array in this area.This paper employs a range-frequency interference structure to frequency-shift compensate the acoustic field at different longitudinal intervals to improve the horizontal-longitudinal correlation of the acoustic field in the shadow zone.Firstly,the range-frequency interference structure and the horizontal-longitudinal correlation are analyzed by simulation based on a deep-sea experimental environment,and the simulated horizontal-longitudinal correlation of the acoustic field is improved through frequency-shift compensation by using an equivalent waveguide invariant.Then the experimental acoustic data from the deep-sea experiment is analyzed.The horizontal-longitudinal correlation of the received acoustic field in the first shadow zone at three depths and two ranges is processed.The data processing results show that the horizontal-longitudinal correlation length after frequency-shift compensation is increased by approximately 4 to 11 times compared to before the frequency-shift compensation.The simulated and experimental results demonstrate that the use of a range-frequency interference structure for frequency-shift compensation of the received acoustic field can effectively improve the horizontal-longitudinal correlation of the sound field in the shadow zone of the deep sea.
