Due to the high-speed movement of a spaceborne radar (SBR) platform, the geographic clutter spectrum expands severely, resulting in the useful moving target signal submerged by the main-lobe clutter background. To deal with this issue, the equipped multichannel arrays in an SBR system provide sufficient spatial degrees, and as a consequence, the space-time adaptive processing (STAP) technology is often preferred to achieve the moving target detection, even in the main-lobe clutter regions. However, for the moving target detection under the sea scene, due to the complex internal motion of sea clutter, the clutter signal received by an SBR system may possess the space- and time-varying characteristics, worsening the multichannel clutter rejection performance using the traditional STAP techniques. In this article, a novel sea clutter suppression method based on the joint space-time-frequency adaptive filtering is proposed. In the proposed algorithm, according to the coherent time analysis of sea clutter, the subaperture time-domain sliding window is employed to alleviate the clutter decorrelation effect, and then, a modified subspace projection technique is applied to accomplish the first-stage clutter rejection. After realizing the effective signal recovery with respect to these residual subaperture clutter data, the second-stage spatial filtering method is applied to realize the final clutter suppression with respect to the relatively high Doppler resolution clutter returns. The effectiveness of the proposed algorithm is verified by both simulated multichannel sea clutter data and real-measured sea clutter data.

中文翻译：

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一种新的星载多通道雷达系统海杂波抑制算法

由于星载雷达（SBR）平台的高速运动，地理杂波频谱急剧扩展，导致有用的动目标信号被主瓣杂波背景淹没。为了解决这个问题，SBR系统中配备的多通道阵列提供了足够的空间度，因此，即使在主瓣中，也经常首选时空自适应处理（STAP）技术来实现运动目标检测。杂乱地区。然而，对于海景下的运动目标检测，由于海杂波内部运动复杂，SBR系统接收到的杂波信号可能具有时空变化的特性，使得传统的多通道杂波抑制性能变差。 STAP 技术。在本文中，提出了一种基于联合空时频自适应滤波的海杂波抑制方法。该算法根据海杂波的相干时间分析，采用子孔径时域滑动窗来缓解杂波去相关效应，然后采用改进的子空间投影技术实现第一级杂波抑制。在实现了对这些残余亚孔径杂波数据的有效信号恢复后，针对多普勒分辨率较高的杂波回波，应用二级空间滤波方法实现最终的杂波抑制。通过模拟多通道海杂波数据和实测海杂波数据验证了所提算法的有效性。