菲律宾海声传播信道时空相关性变化实验

Experimental study about correlation vacation of acoustic propgation channel in philipping sea

声传播信道的时空相关性变化主要由信道多途结构的时空变化所决定。一般深海声传播信道由于受海底底质影响小，多途结构相对较为简单，比较容易实现深海信道的修正匹配．本文利用拖曳式低频宽带大功率发射换能器，发射线性调频脉冲信号，在接收端利用拷贝相关和脉间相关处理，得出信道的时空相关性变化。由于采用了宽带长脉冲信号，经过处理后减少了噪声于抗的影响．实验结果证实：信道的时空相关性主要由信道的多途结构及其时空变化决定．信道的相干部分约占全信道的４０％．本文的实验结果对深海信道的修正匹配研究有一定参考价值。

The correlation variation of acoustic propgation channel is mainly caused by time space variation of the multipath structure of acoustic channel. In general, acoustic channals in deep sea have more simple multipath structure due to less influence. of the sea bottom. So in deep sea the correction match of acoustic channel could be more easy realized. In this experiment, a towed powerful low freqency transducer is used to transmit linear freqency modulated pulse, and at the receiving terminal the copy correlation and the pulse to pulse correlation were used to obtain the time space variation of acoustic channel correlation. Du to the application of wide band, long duration pulse and signal processing, the noise influence is reduced to minimum.Therefor our experimental .results proved that the time space correlation of acoustic channel is mainly determined by the time space variation of channel's multipath structure, and coherent part of such a multipath channel makes up about 40 per cent of its total. The experimental results described in this paper could be helpful to study the correction match of the deep sea acoustic channel.