空天群目标逆合成孔径雷达高分辨成像方法研究

In high-resolution ISAR imaging of airspace group targets, echoes of the sub-targets may overlap in the range domain. Further, the sub-targets generally possess complex motion. To tackle these problems, this project derives signal models in different scenarios. Based on detailed analyzes of the time-frequency distribution as well as motion features of the sub-targets, techniques for high-resolution ISAR imaging of airspace group targets are proposed from four aspects, i.e. imaging of maneuvering rigid group targets, imaging of micro-motion group targets, imaging of group targets with a low pulse repitition frequency and random initial phase error, and imaging of micro-motion group targets with complex motion based on scatterer trajectory tracking. Finally, high-resolution two-dimensional or three-dimensional imaging and feature extraction of airspace group targets are realized in different conditions, which will greatly improve the radar's ability in detection and recognition of airspace group targets.

针对空天群目标逆合成孔径雷达高分辨成像中子目标回波混迭和运动复杂等难题，本项目将建立不同观测条件下的回波模型，通过对空天群目标回波时频分布特性和运动特性的分析，对机动刚体群目标成像、微动群目标成像、方位欠采样和存在随机初相误差条件下的空天群目标高分辨成像，以及基于散射点航迹跟踪的复杂微动群目标成像等方法进行深入研究，最终实现不同观测条件下的群目标高分辨二维或三维成像和特征提取，从而显著提高我国成像雷达对空天群目标的探测和识别能力。

通过对空天群目标的高分辨逆合成孔径雷达（ISAR）成像研究，可以获得群目标中子目标的数量、几何尺寸、几何结构和运动参数等特征物理信息，从而进一步提高ISAR的目标探测和识别等信息获取能力。本项目重点对刚体群目标、微动群目标、复杂微动群目标高分辨ISAR成像等三方面内容开展研究工作。在刚体群目标ISAR成像方面，提出匀加速直线运动编队目标ISAR成像方法和基于PSO与修正CLEAN技术的刚体群目标ISAR成像方法。在微动群目标高分辨ISAR成像方面，建立了锥体、柱体等典型空间微动目标的散射中心分布模型，研究了基于时域变标的旋转群目标统一平动补偿方法和基于匹配滤波的高分辨成像方法，进一步研究了基于曲线拟合与匹配滤波的进动目标固定散射点高分辨三维成像和微动参数估计方法。在复杂微动群目标高分辨ISAR成像方面，提出基于航迹关联与矩阵分解的复杂微动目标高分辨成像方法，进一步提出基于增广拉普拉斯算子法和K-均值聚类的复杂微动群目标高分辨成像方法。相关研究工作将为提高我国成像雷达的空间态势感知能力提供技术支撑。