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对于复杂的海洋传播环境,如波导环境扰动、各阶模态之间的干涉、环境噪声等,声信号在传播过程中波形会随空间和时间起伏变化.接收信号之间的空间相关性是直接影响阵列处理增益的重要因素之一,因此研究信号的空间相关特性对提高信号处理的性能有重要意义.本文中,利用一次海上试验测量数据对陆架斜坡海域不同位置处接收信号的水平纵向相关特性以及水平纵向相关性随船运动的起伏变化情况进行了研究.海上试验在中国南海海域开展.试验中,接收阵为一个192元水平拖曳阵,以2 m/s的速度移动,声源为一个宽带声源,深度为95 m左右,用钢缆与发射船船尾相连.实验过程中发射船停机漂泊.声源发射信号为260–360 Hz的线性调频信号.为了降低环境噪声对水平纵向相关性测量结果的影响,数据处理过程中先对接收信号进行带通滤波和匹配滤波处理.然后,将接收阵划分若干个部分重叠的短的子阵列并对各子阵接收信号进行宽带波束形成处理.最后,利用各子阵宽带波束形成输出信号计算水平纵向相关系数.结果发现,该海域接收信号水平纵向相关长度的测量结果大体分布在13–60 m的范围内,普遍小于浅海波导环境,信号水平纵向相关特性易受斜坡海域声场干涉结构和海洋波导环境起伏的影响,随空间和时间变化明显.
For complex marine propagation environment, such as disturbance of waveguide environment, interference between various modes, environmental noise, etc., the waveform will change with space and time during the propagation of acoustic signal.The spatial correlation between received signals is direct Therefore, it is of great significance to study the spatial correlation of signals to improve the performance of signal processing.In this paper, the horizontal longitudinal correlation characteristics of received signals at different positions on the shelf slopes are measured using a single marine test measurement data As well as the horizontal and vertical correlation with the ups and downs of the ship’s movement.The marine test was carried out in the South China Sea.At the test, the receiving array was a horizontal towed array of 192 yuan moving at 2 m / s with a sound source Broadband sound source, the depth of about 95 m, with the cable connected to the stern of the launch vessel during the experiment launch launchers drift sound source emission signal for the 260-360 Hz chirp signal in order to reduce the environmental noise horizontal horizontal correlation The impact of measurement results, the data processing process of the first received signal band-pass filter and matched filter processing.Then, the receiving array Divided into a number of partially overlapping short sub-array and each sub-array receive signals for wideband beamforming processing.Finally, using the sub-array wideband beamforming output signal to calculate the horizontal longitudinal correlation coefficient.It was found that the sea level received signal horizontal correlation The results of length measurements are generally distributed in the range of 13-60 m, which are generally less than those in shallow sea wave guides. The longitudinal correlation of signal level is easily affected by the sound field interference structures in sloping seas and the undulation of ocean wave guides, with obvious changes with time and space.