基于空域联合时频分解的海面慢速小目标检测新方法

These difficulties, such as the double non-stationary of both sea clutter and the echoes of the small target, the feature of the “spike” that is similar to the echoes of the small target, and the aliasing of the spectra of sea clutter and echoes of the small target, block the development of the slow-moving small target detection seriously.. To overcome the above difficulties, this project studies jointly decomposition of multi-signals in the time-frequency domain, involving the theories of high resolution unambiguous time-frequency analysis, cross-term suppression, and inverse time-frequency transform. Focusing on the correlation of the sea clutter in space, this project establishes the new theory and method of the joint spatial time-frequency decomposition, constructs the “spike” suppression method based on the correlation between the decomposed components, and establishes the slow-moving small target detection methods based on the multiple time-frequency decomposition feature fusion. The aim of this project is to analyze the non-stationaries of both sea clutter and the echoes of the small target in high resolution radar systems, to jointly decompose multi-signals in the time-frequency domain, to suppress the strong sea clutter/echoes of “spike”, and to construct the method of multiple feature fusion. This project can provide the new theories and methodologies for detecting a small target in sea clutter by a high resolution radar, which can detect a slow-moving small target quickly. This project is of great application value in antisubmarine, sea surveillance, maritime search and rescue, and precision guidance.

海杂波与小目标回波的双重非平稳性、海“尖峰”的类目标特征、海杂波与慢速小目标回波的频域混叠特性等困难严重影响了海面慢速小目标检测技术的发展。. 针对以上困难，本课题以多信号联合时频分解方法为研究内容，涉及高分辨无模糊时频分析理论，交叉项抑制理论和时频逆变换理论。结合海面回波的空域相关性，研究并建立海面回波的空域联合时频分解新理论和新方法；研究并建立基于分解分量空域相关性的海“尖峰”回波抑制方法；研究并建立基于多重时频分解特征融合的海面慢速小目标检测新理论和新方法。突破高分辨雷达下海杂波和海面小目标的非平稳性分析、多信号联合时频分解方法建立、海“尖峰”回波抑制、特征融合检测方法构建等技术难点，提出高分辨雷达海面小目标检测新理论和新方法，从而实现慢速小目标的快速检测，为反潜作战、海面监视、海上搜救、精确制导等提供理论方法和技术支撑。

本课题以多信号联合时频分解方法为主要研究内容，并将该信号分解方法应用到海面慢速微弱目标检测中。主要研究了高分辨无模糊时频分析理论，高分辨无模糊时间－调频率分布理论、交叉项抑制理论和时频逆变换理论，提出了两信号联合时频（时间－调频率）分解方法。由于目标的存在会改变其所在水域的海面运动状态，所以在空间上目标会表现出较长的相关距离，而海“尖峰”的相关距离较短。所以取不同距离单元的回波信号作为多信号联合时频分解方法的输入，可以同时分解这两个距离单元的回波。对于分解分量，研究并建立基于多重特征融合的海面慢速小目标检测新理论和新方法。从而实现慢速小目标的快速检测，为反潜作战、海面监视、海上搜救、精确制导等提供理论方法和技术支撑。