中文摘要：

匹配滤波器作为高斯白噪声背景下线性调频信号的最优检测器,在水下声信号处理中得到了广泛的应用.根据匹配滤波器输出峰值位置可以获得目标距离的估计,但运动目标径向速度造成的回波和样本失配将导致匹配滤波器检测性能下降.利用分数阶傅里叶变换对线性调频信号的聚焦特性,提出了应用离散分数阶傅里叶变换的水下运动目标线性调频回波检测算法.仿真测试表明,该算法对于混响噪声背景下径向速度未知动目标的线性调频回波具有良好的检测性能.

英文摘要：

As the optimal detector under white Gaussian noise background, the matched filter is widely used in the domain of underwater acoustic signal processing, and the estimation of target range can be achieved according to the peak position of the matched filter＇s output. But the mismatch between echo and replica caused by moving target＇s radial velocity will degrade the detecting performance of the matched filter. Using the focusing property of FRKl＇（Fractional Fourier Transform） for LFM（Linear Frequency-Modulated） signal, the detecting algorithm for the LFM echo of underwater moving targets based on DFRFT（Discrete Fractional Fourier Transform） is proposed. The simulation test shows this algorithm performs well for the LFM echo of moving target with unknown radial velocity under reverberation background.