海底声学原位测试声速提取技术研究

海底沉积物的声学声速特性是沉积物声学中的一个重要的研究方向。正确提取声学原位测量的声速对海底沉积物声学反演至关重要。分析了海底声学原位测试系统的输出子波特性,提出了基于子波提取的互相关双向极值声速提取法。在声速提取过程中,发现某些通道实测声波到达时会出现超出正常范围的异常。分析后认为异常通道的到达波相位出现180°反至现象。通过互相关数值的负极小值提取的声波到达时对互相关正极大值所获得的到达时曲线进行校正后提取声速,得到了正确的结果,说明了本方法的正确性。

Study on Sound Speed Picking-up Technique by Geoacoustically Measuring In-situ Marine Sediment

The marine sediment acoustic characteristics are an important research direction in sediment acoustics,and the correct pick-up of in-situ marine sediment sound speed is of great importance to the marine sediment acoustics inversion.In this paper,the output wavelet characterisitics of in-situ marine sediment geoacoustic measuring system are analyzed,and a cross-correlation two-way extreme value sound speed picking-up method based on wavelet pick-up is then proposed.In the sound speed pick-up process,it is shown that the anomalies of measured sound wave arrival times for some channels occurred,and it is concluded that the arrival sound wave phases for the abnormal channels are reversed.The sound wave arrival time curve obtained by finding the cross-correlation positive maxima is rectified by the sound wave arrival times obtained by finding the cross-correlation negative minima to pick-up the sound speed,and correct results are obtained,which indicates the correctness of this method.