Target detection in sea clutter is of great significance in military radar research. Because the characteristics of sea clutter are complex and easily affected by wind direction, the method of suppressing sea clutter by using sea clutter characteristics to reproduce is not advantageous. To address this problem, this article focuses on the direct extraction of the target echo. According to the difference in fractional characteristics between the target echo and sea clutter, fractional Fourier transform (FRFT) is introduced to extract the target echo. In this article, a fractional domain change coefficient clustering method is established to identify the range units of the target, and a fractional domain filtering method based on the minimax is proposed to extract the target spectrum of target-dominated range units, so as to separate the target echo from sea clutter. Simulated and measured experiments prove that this method can accurately identify targets and extract target information under various sea states and a different number of targets.

中文翻译：

---

基于分数阶傅里叶滤波的海杂波自适应目标提取方法

海杂波中的目标检测在军用雷达研究中具有重要意义。由于海杂波特性复杂且易受风向影响，利用海杂波特性再现抑制海杂波的方法并不具有优势。为了解决这个问题，本文着重于目标回波的直接提取。根据目标回波与海杂波分数特征的差异，引入分数阶傅里叶变换（FRFT）提取目标回波。本文建立了一种分数域变化系数聚类方法来识别目标的距离单元，并提出了一种基于极小极大值的分数域滤波方法来提取目标主导的距离单元的目标谱，从而将目标回波与海杂波分离。仿真和实测实验证明，该方法可以在各种海况和不同目标数量下准确识别目标并提取目标信息。