基于极化信息时频分布的紧凑型高频地波雷达超分辨测向方法研究

High Frequency Surface Wave Radar(HFSWR)has the low performance for measuring degree of arrival(DOA) of target due to working frequency (3MHz-30MHz) limitation. Large size antenna array is always used in HFSWR system to meet precision requirement for target direction-finding. Considering experiment's place resource shortage at seaside, in civilian areas, it is difficult to find a suitable field to layout HFSWR system with huge attena array. It is the development trends of the future HFSWR that the compact antenna array is combined with high precision super resolution direction finding alogrithm. The traditional spatial spectrum super resolution algorithm uses only one-dimensional spatial information, the signal, besides spatial information, also contains polarization information and time frequency information, the signal spatial spectrum estimation accuracy can be further improved if the multi-dimensional information can be fully used. Based on distance spectrum of compact HFSWR used LFMICW signal, aiming at non-stationary and polarized characteristic of target echos, by building a compact HFSWR experimental system with dual-polarized antenna array, this program will use time-frequency distribution of radar echoes and furthermore exploits polarization information to improve performance of spatial spectrum estimation and develops the optimization alogrithm of super-resolution direction finding to solve the problem of low azimuthal accuracy for detecting ship target at the sea and offers a new way to improve detection ability to targets for compact HFSWR.

高频地波雷达受工作频率（3MHz-30MHz）限制，测向精度较低。为满足雷达系统测向精度，通常采用大尺寸天线阵列。考虑到海边场地等资源紧缺，大尺寸天线阵列占地面积巨大，目前民用领域很难找到合适的雷达场地。采用紧凑型天线阵列辅以高精度超分辨目标测向算法是高频地波雷达未来发展趋势，传统的空间谱超分辨测向算法只利用了信号的空间一维信息，空间信号除方位信息外，还包含信号的极化信息、时频信息，充分利用多维度信息可以提高信号空间谱估计精度。本课题拟从线性调频体制紧凑式高频地波雷达距离谱出发，针对雷达回波信号的非平稳特征和极化特性，构建紧凑型极化天线接收阵列高频地波雷达实验系统，利用目标回波的空间时频分布特性，充分挖掘极化信息对提升目标方位估计精度作用，研究发展最优的极化时频空间谱估计超分辨算法，解决紧凑型高频地波雷达探测海上船只目标时的方位精度问题，为提升紧凑型高频地波雷达目标探测性能提供思路。

高频地波雷达受工作频率（3MHz-30MHz）限制，测向精度较低。为满足雷达系统测向精度，通常采用大尺寸天线阵列。考虑到海边场地等资源紧缺，大尺寸天线阵列占地面积巨大，目前民用领域很难找到合适的雷达场地。采用紧凑型天线阵列辅以高精度超分辨目标测向算法是高频地波雷达未来发展趋势，传统的空间谱超分辨测向算法只利用了信号的空间一维信息，空间信号除方位信息外，还包含信号的极化信息、时频信息，充分利用多维度信息可以提高信号空间谱估计精度。本项目构建了紧凑型双极化高频地波地波雷达实验平台，在分析雷达目标和杂波特性的基础上，利用目标回波的空间时频分布特性联合极化信息展开目标超分辨算法研究，先后发展了极化时频MUSIC和ESPRIT联合估计算法，强杂波背景下弱信号的时频特征交叉项提取方位估计算法以及互质极化敏感阵列下的回波目标方位估计等算法，重点解决紧凑型高频地波雷达探测海上船只目标时的方位精度问题，通过实际录取的数据进行了验证。另外，在课题研究过程中，由于雷达发射波束仰角不理想，导致一部分发射能量进入天波传播，在回波中包含较强的电离层杂波干扰，为了更好的抑制该电离层杂波，本项目对电离层特性和传播路径模型也进行了初步研究。本项目共发表期刊论文10篇，其中SCI 论文8篇，EI会议论文9篇，申请发明专利一项，获军队科技进步二等奖一项。