海杂波FRFT谱的近似分形特性与目标检测  

Approximate Fractality of Sea Clutter FRFT Spectrum and Target Detection

作　　者：宋杰[1,2] 刘宁波[2] 王国庆[2] 关键[2] 何友[2] 

机构地区：[1]北京理工大学信息与电子学院,北京100081 [2]海军航空工程学院电子信息工程系,烟台264001

出　　处：《宇航学报》2013年第10期1394-1402,共9页Journal of Astronautics

基　　金：国家自然科学基金(61002045;61179017;61201445);"泰山学者"建设工程专项经费和博士后基金(2012M520174)

摘　　要：主要介绍了海杂波分数阶Fourier变换(FRFT)谱的近似分形特性及其在海杂波目标检测中的应用。根据FRFT的尺度变换性质,研究了自相似过程FRFT谱的近似分形特性,然后将近似分形分析方法引入到实测海杂波FRFT谱分析中,发现在特定变换阶数下得到的海杂波FRFT谱间存在近似分形特性,且目标回波可使近似分形特性描述参数——FRFT域Hurst指数发生变化。因此,可利用FRFT域Hurst指数设计恒虚警率(CFAR)检测方法。经X波段和C波段雷达实测数据验证,所提方法的检测性能明显优于经典的利用时域Hurst指数的目标检测方法。The approximate fractality of the fractional Fourier transform （FRFT） spectrum of sea clutter and its application of the approximate fractal characteristic of the sea clutter FRFT spectrum in target detection are mainly studied. According to the scale transformational property of FRFT, the approximate fractality of the FRFT spectrum of a self-similar process is studied. Then, an analytical method of approximate fractality is introduced to analyze the FRFT spectrum of real sea clutter. It＇ s found that approximate fractality exists among the sea clutter FRFT spectra of some specific transform orders. Moreover, target echoes can cause the descriptive parameter of approximate fractality, or the Hurst exponent in FRFT domain to change. Therefore, the Hurst exponent in FRFT domain can be used to design the CFAR detection algorithm. By verifying measured data of X-band and C-band radar, the proposed method performs much better than the classical detection method usina the Hurst exoonent in time domain.

关 键 词：海杂波 FRFT谱 分形 相似性 目标检测 

分 类 号：TN957[电子电信—信号与信息处理]