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提出了一种利用辐射噪声多线谱的多普勒频移去估计直线匀速运动目标正横距离的方法,这种方法用单水听器进行无源测距,且不需要知道海深和其它环境参数。先用Wigner-Ville分布作为瞬时频率估计器估计出多线谱瞬时频率随时间变化作为一个信号,再定义多普勒频移的基函数,依据一种匹配投影原理,在五维空间中用一种可变步长的搜索策略去寻找该信号与多普勒频移基函数之间的最小空间距离。所找到最小距离的基函数对应于目标距离和速度的估计值。计算机模拟给出不同强度干扰噪声下的测距测速的统计误差。当干扰噪声的标准差为最大多普勒频移的10％及时间窗宽度为1．47倍的参考时宽时,测距相对误差小于5．4％,测速相对误差小于1．4％。对某海上实际目标的距离估计为42 m,速度为52 kn,与实际航行的值相符。此单点无源测距方法可应用于声呐浮标、水雷、水声实验中水声目标的运动分析和水下目标声源级测量。
A method is proposed to estimate the vertical moving distance of a linear uniform moving object by using the Doppler shift of radiated noise multispectral. This method uses a single hydrophone to perform passive ranging and does not need to know the sea depth and other Environmental parameters. Firstly, the Wigner-Ville distribution is used as an instantaneous frequency estimator to estimate the instantaneous frequency of multi-line spectrum as a signal and then define the basis function of Doppler shift. According to a matching projection principle, A variable step search strategy is used to find the minimum spatial distance between the signal and the Doppler frequency shift basis function. The basis function for the smallest distance found corresponds to an estimate of the target distance and speed. Computer simulation gives the statistical error of range-measuring speed under different intensity interference noise. When the standard deviation of the interference noise is 10% of the maximum Doppler shift and the time width of the time window is 1.47 times, the relative error of the ranging is less than 5.4% and the relative error of the speed is less than 1.4%. The actual distance to an actual target at sea is estimated to be 42 m at a speed of 52 knots, commensurate with the actual value of the voyage. This single-point passive ranging method can be applied to the acoustic analysis of underwater acoustic targets and submarine target sound-source measurements in sonar buoys, mines and underwater acoustic experiments.