天发岸收混合体制高频雷达展宽海杂波建模与抑制方法研究

Based on the propagation mode associated with sky-wave transmitting and shorebased surface-wave receiving, HF hybrid sky-shorebased surface wave radar not only maintains the superiority of HF skywave radar which have a long detection rang and wide coverage, the advantage of HF surface wave radar which have a stable propagation channel, but also keeps a good invisibility and anti-interference ability. However, the sea clutter under this combined propagation mode with sky-wave transmitting and shore-based receiving is influenced by composite factors such as the bistatic angle and ionospheric phase disturbance. Therefore, the width and shape of sea clutter Doppler spectrum will be broaden and complicated, giving rise to the severe restriction of ship target detection. Firstly, the internal mechanism and characteristics of the broadening sea clutter based on the detection principle of HF hybrid sky-shorebased surface wave radar are studied deeply and carefully in this dissertation. Secondly, the broadening first-order sea clutter model for HF hybrid sky-shorebased surface wave radar is established. The theoretical analysis of sea clutter characteristics and broadening sea clutter model are examined by measured data. Eventually, based on the preceding established broadening sea clutter model and characteristics, the techniques to suppress the broadening sea clutter are studied. The research in this project will provide the theory and technology foundation to detect the target over the horizon under the broadening sea clutter in HF hybrid sky-shorebased surface wave radar.

基于天波发射-岸基地波接收组合传播模式下的高频超视距雷达兼具天波传播距离远、覆盖范围大以及地波绕海面传播稳定的双重优点，并且具有双基地雷达固有的隐蔽性和抗干扰能力。然而天发-岸组合传播模式下的海杂波受双基地角以及电离层扰动等因素的复合影响，海杂波谱展宽严重且形态复杂，严重影响舰船目标的检测。本项目依据天发-岸收组合模式高频雷达的探测原理，深入分析海杂波展宽的内在机理和特性，建立展宽海杂波模型，在此基础上开展海杂波抑制和目标检测方法研究，并利用实测数据分别对海杂波模型和抑制方法进行验证。本项目的研究可为天发-岸收组合模式高频雷达实现展宽海杂波背景下的目标检测提供一定的理论基础和技术支持。

本课题通过深入分析天发地收混合体制高频雷达海杂波展宽的内在机理和特性，建立了海杂波展宽模型，在此基础上开展了展宽海杂波抑制方法研究，并利用实测数据分别对海杂波模型和抑制方法进行了验证。主要进展及创新点如下：（1）提出了天发地收高频雷达一阶海杂波Bragg频率以及频谱展宽空间分布的计算模型。该模型可以从理论上定量地描述和揭示一阶海杂波Bragg频率的理论分布和展宽特性与雷达参数、电离层以及系统布局等因素的内在关系。（2）基于Bragg散射理论建立了天发地收组合模式下的一阶海杂波展宽模型，该模型能够较好地描述实际一阶海杂波的分布和展宽特性，实测数据验证了其正确性和合理性。在建立海杂波展宽模型过程中，取得了以下创新性成果：基于Bragg散射理论和散射区均分法建立了天发地收理想宽波束下的双基地展宽海杂波谱模型；从电离层介质特性和相径扰动产生机理的角度出发，提出了一种基于电离层传播特性的相径扰动模拟方法。（3）提出了一种基于电离层相径扰动校正与海杂波抑制的级联处理方法。该级联处理方法有效抑制了复合因素作用下的展宽海杂波。（4）基于局域联合处理算法(JDL)算法分析了展宽海杂波的空时联合抑制性能，并提出了基于先验知识的空时联合海杂波抑制方法。该方法更好地抑制海杂波和尽量避免被海杂波淹没的目标信息被抑制掉的目的。（5）提出非平稳展宽杂波环境下目标与杂波区分的检测算法，实测数据验证了算法有效性。针对基于广义似然检测思想的AMF目标检测算法存在计算复杂度大问题，提出适合工程运算要求的自适应匹配滤波平滑处理的(AMF-FS)目标检测算法；针对杂波的“类目标”特性导致杂波抑制算法效果不好的问题，提出基于动态规划检测前跟踪算法(DP-TBD)目标与杂波区分的目标检测方法。.基于以上研究成果，在本领域国内外期刊和学术会议上发表论文23篇，其中SCI收录4篇、EI收录12篇、国内会议论文3篇、其它中文期刊4篇。申请国家发明专利15项、申请软件著作权1项。