基于分数傅里叶极化估计的高频雷达电台干扰抑制

目标探测高频雷达工作在短波波段的低频段(3~15 MHz), 该波段内密集的短波电台对高频雷达的目标探测能力造成严重影响, 必须对电台干扰加以抑制才能保证高频雷达全天候正常工作.极化滤波是抑制高频雷达中短波电台干扰的有效方法, 但需要对干扰和目标信号的极化参数进行精确估计.文章在基于分数阶傅里叶变换(Fractional Fourier Transform, FrFT)准确估计目标和干扰极化参数的基础上, 利用估计的目标和干扰极化参数来构建极化子空间, 通过极化斜投影算子对高频雷达中的电台干扰进行抑制.实测数据处理结果表明, 基于FrFT的估计方法能准确估计出回波信号中电台干扰的极化状态, 在此基础上进行的斜投影极化滤波能有效抑制高频雷达电台干扰, 提高雷达探测性能.

FrFT polarization estimation based radio interference suppression for high frequency surface wave radar

The performance of the high frequency surface wave radar (HFSWR), which works at the shortwave band (3-15 MHz), degrades heavily in an intensive radio interference environment. The radio interferences must be suppressed to ensure HFSWR all-weather operations. Polarization filtering is an effective method to suppress radio interferences, but the polarization parameters of signal and interference must be accurately estimated. On the basis of polarization parameters exact estimation by fractional Fourier transform (FrFT), a subspace is constructed using those estimated parameters, and the oblique projection operator is used to suppress radio interferences for HFSWR. The processed real data indicate that: the polarized parameters of the target and the radio interference can be estimated exactly by FrFT; the radio interferences can be effectively suppressed; the detection performance of HFSWR is further improved.