SAR图像中舰船目标恒虚警率检测技术的研究  

Research on Constant False Alarm Rate Detection Technique for Ship in SAR Image

作　　者：孟祥伟 MENG Xiangwei(Department of Electrical and Electronic Engineering,Yantai Nanshan University,Yantai 265713,China)

机构地区：[1]烟台南山学院电气与电子工程系,烟台265713

出　　处：《电子与信息学报》2024年第9期3739-3748,共10页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62171402)。

摘　　要：在各种各样的合成孔径雷达图像舰船目标检测方法中,应用最广泛、最重要的就是具有自适应阈值的恒虚警率(CFAR)检测器。为了提高SAR图像中舰船目标的检测性能,人们试图通过各种统计分布模型对SAR图像中的杂波背景进行统计建模,如Gamma分布、K分布、对数正态分布、G0分布、alpha稳定分布等,再通过相应的统计分布模型以及各种样本筛选技术的CFAR检测器对舰船目标实施检测。SAR图像中杂波背景是复杂多变的,当实际杂波背景与假定统计分布失配时,参量型CFAR检测器的性能会恶化,非参数CFAR检测器就会显示出优势。该文提出了基于Wilcoxon非参数检测器的新途径对SAR图像中舰船目标进行检测,并在Radarsat-2,ICEYE-X6和Gaofen-3卫星的实测数据上,与几种典型的参量型CFAR检测方法进行了对比。实验结果表明,Wilcoxon非参数检测方法在这3种实测数据上的虚警控制能力具有良好的鲁棒性,还可以带来弱目标检测性能的改善,具有运算速度快、易于硬件实现的特点。Among various methods to detect the ship targets in Synthetic Aperture Radar(SAR)image,the Constant False Alarm Rate(CFAR)detection algorithm with an adaptive detection threshold is the most important and extensively used one.In order to improve the detection performance for ships in SAR image,various statistical distributions are applied,with an attempt to accurately model the SAR clutter backgrounds,such as Gamma distribution,K distribution,log-normal distribution,G0 distribution and the alpha-stable distribution,etc.In modern radar systems,the use of the CFAR technique is necessary to keep the false alarms at a suitably low rate in an a priori unknown time-varying and spatially nonhomogeneous backgrounds,and to improve the detection probability as much as possible.The clutter background in SAR images is complicated and variable,when the actual clutter background deviates from the assumed statistical distribution,the performance of the parametric CFAR detectors deteriorates,whereas the nonparametric CFAR method exhibits its advantage.In this paper,the Wilcoxon nonparametric CFAR scheme for ship detection in SAR image is proposed and analyzed.By comparison with several typical parametric CFAR schemes on 3 real SAR images of Radarsat-2,ICEYE-X6 and Gaofen-3,the robustness of the Wilcoxon nonparametric detector to maintain a good false alarm performance in these different detection backgrounds is revealed,and its detection performance for the weak ship is improved evidently.Moreover,the detection speed of the Wilcoxon nonparametric detector is fast,and it has the simplicity of hardware implementation.

关 键 词：SAR图像 雷达杂波 目标检测 恒虚警率 非参数 

分 类 号：TN957.51[电子电信—信号与信息处理]