利用声场频谱频率漂移监测内波的算法改进和实验验证

声场频谱的频率漂移曲线可以用来监测内波。由于简正波幅度剧烈起伏带来的干扰,目前尚无从实验数据中提取频移曲线的有效算法.提出了一种依据实测声学传播数据提取频移曲线的算法。借助于简正波过滤技术,该算法利用相关法从简正波相角之差中提取频率漂移曲线。利用该算法提取的频移曲线与内波导致的跃层起伏具有很高的相似性,这在2011年黄海实验中得到了验证。该算法的优点是可以保留简正波相位差变化导致的频移曲线信息,同时又能有效地抑制简正波幅度起伏带来的干扰,但是需要良好的接收阵阵型来保证简正波分离。 

The algorithm improvement and experimental confirmation of monitoring internal waves using the frequency shifts of acoustic intensity spectrum

The frequency shifts of acoustic intensity interference pattern could be used to monitor the internal waves. But there wasn't an effective method to extract the frequency shift line from the experiment data because of the huge fluctuation of acoustic mode's amplitude. An improved method for the extraction of frequency shift line from experiment data was proposed. With the help of mode filtering the method used the correlation function to extract the frequency shift line from the difference of the phase angles of the modes. The extracted frequency shift line has great similarity with the thermoeline depth variance caused by internal waves, which is proved by the experiment in Yellow Sea 2011. This method could preserve the frequency shifts caused by the change of acoustic modal phase difference, while at the same time restrain the disturbance of the acoustic mode amplitude' fluctuation, but needed a fine layout of the receiver line array to ensure the mode separation of the normal modes.