采用收发极化联合优化的极化雷达目标检测新算法

A novel target detection algorithm of polarimetric radar based on joint transmit and receive polarization optimization

针对极化雷达在非高斯杂波背景下的未知目标检测问题,建立了一种收发极化可变的全极化雷达测量模型,提出了一种基于广义似然比检测的收发极化优化目标检测器,并得到了检测判决量的闭环形式。在性能分析环节,推导得到了该检测器检测性能的解析表达式,指出了它的恒虚警性质,明确了收发极化矢量与检测性能之间的对应关系。在性能验证环节,首先设计了非高斯杂波背景下的目标检测实验,结果表明,在相同的实验条件下,本文检测算法的抗杂波非高斯性能和检测性能优于现有典型目标先验信息未知的极化检测器,性能接近目标和杂波先验信息已知的最优极化检测器。接着对比了收发极化联合优化、发射极化优化和收发极化固定3种极化雷达的目标检测性能,结果表明,在相同的实验条件下,收发极化联合优化的极化雷达具有最优的目标检测性能。

As to the unknown target detection for polarimetric radars under the background of non-Gaussian clutter,a measurement model of the fully-polarimetric radar with variable transmit and receive polarization is built.Then by employing the generalized likelihood ratio test（GLRT）,a novel polarimetric detector based on joint transmit and receive polarization optimization is proposed and the close form of the test statistics is obtained.Furthermore,in the stage of performance analysis,its analytical expression of detection performance is derived.Remarkably,the newly proposed detector has the constant false alarm rate（CFAR）property.Moreover,the correspondence between the polarization vector and the detection performance is clarified.Finally,in the stage of performance assessment,we firstly design the experiment of the unknown target detection under the non-Gaussian clutter background.The results show that,withthe same experimental conditions,the proposed algorithm has a better performance against non-Gaussian clutter than the existing polarization detectors for unknown targets,and also a better detection performance than them,while the detection performance of the proposed detector is close to the optimal polarization detector（OPD）,which is with a prior knowledge of the target and clutter.Then we compare the detection performances of the polarimetric radar with joint transmit and receive polarization optimization,the one with only transmit polarization optimization and the one with fixed transmit and receive polarizations.The results show that under the same experimental conditions,the detection performance of the aforementioned first radar system is better than the latter two systems.