浅海中运动声源径向速度与距离的无源估计

针对浅海波导中声源距离的无源估计问题,提出了一种环境参数和声场模型无关的、不依赖于引导声源的运动声源径向速度以及距离估计方法。该方法首先通过双水听器低频声场强度距离波数谱变换(R-K)的相位差获得干涉简正波水平波数,对水平波数轴定标来估计运动声源的径向速度。进一步地,对接收信号自相关函数进行WARPING变换得到运动声源距离的无源估计。对于反射类简正波为主的声场,在某一假定距离下根据某两时刻接收信号WARPING变换后干涉简正波谱峰频率与假定距离的关系估计距离;对于反射类或折射类简正波为主的声场,根据两个时刻接收信号的β-WARPING变换后干涉简正波的脉冲时延估计距离的值。数值仿真分析了等声速、负梯度以及温跃层3种水文环境下的噪声以及环境宽容性,结果表明径向速度与距离的估计不依赖于环境参数。利用2005年北黄海实验数据验证了方法的可行性,径向速度与距离的估计值与实际值符合良好。 

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.