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为在噪声中有效提取水下目标回波,提出一种基于经验模态分解的目标回波提取方法,分别对目标回波与噪声进行经验模态分解,得到二者各阶的固有模态信号分量;计算二者各阶的固有模态分量的能量,求取对应各阶的能量差,并与门限相比较,选取大于门限的固有模态分量重构目标回波信号.分析了经验模态分解阶数和选择门限等因素对重构信号精度的影响.仿真结果表明,该方法可精确提取目标回波.采用该方法提取信号的均方误差均低于自适应滤波方法,尤其在低信噪比时.
In order to effectively extract underwater target echoes in noise, a method of target echoes extraction based on empirical mode decomposition is proposed. Empirical mode decomposition is performed on target echoes and noise respectively to obtain the natural modes The energy of the natural modal components of each of the two orders is calculated and the energy difference corresponding to each order is calculated and compared with the threshold to select the natural modes components larger than the threshold to reconstruct the target echo signals.The empirical mode The decomposition order and the selection threshold and other factors on the accuracy of the reconstructed signal.The simulation results show that the method can accurately extract the target echo.The mean square error of the signal extracted by this method is lower than the adaptive filtering method, When the noise ratio.