基于分数阶模糊函数的海面运动弱目标检测

Weak target detection in sea clutter based on fractional ambiguity function

通过推导单频信号、线性调频信号和含有三次项信号的正负对称旋转角的分数阶模糊函数,得到一个有用的结论:单频信号和线性调频(linear frequency modulation,LFM)信号正负对称旋转角的分数阶模糊函数模函数处处相等,而对于含有三次项的回波信号,其模幅度差别很大。根据此特性提出了一种海杂波背景下的基于正负旋转角的分数阶模糊函数模函数对消的运动弱目标检测方法。通过对智能像素处理(intelligent pixel-pro-cessing,IPIX)雷达实测数据验证表明,所提方法在增加目标与杂波分数阶模糊函数峰值差、提高信杂比等方面都明显优于仅对回波作分数阶模糊函数。采用双参数恒虚警检测方法设置适当的门限,文中研究的检测方法能够达到更好的检测效果。

The fractional ambiguity function models with two symmetry inverse rotation angles of linear frequency modulation（LFM） signal,monochromatic signal and polynomial signal are researched.A conclusion is obtained： the fractional ambiguity function models with two symmetry inverse rotation angles of LFM signal and monochromatic signal are always the same.Based on this characteristic,a new method for detecting the signal which has high polynomial based on difference of fractional ambiguity function model is proposed.Experiment using the intelligent pixel-processing（IPIX） data shows that the proposed method has a remarkable advantage in increasing the signal-to-clutter ratio（SCR） and fractional ambiguity function model peak value difference.A proper detective threshold is set by introducing the biparametric constant false alarm rate,which makes the proposed method achieve better effects.