海杂波背景下小目标检测的分形方法

针对海杂波背景下小目标检测对海情依赖性强的问题, 本文采用分数布朗运动模型对实测海杂波建模, 结合多重分形去势波动分析法确定分形参数, 分析了海杂波的单尺度、多重分形特性. 在单尺度分形的基础上, 利用表征海杂波分形特征的分数维和Hurst指数构建了分形差量, 提出了基于分形差量的小目标检测方法;在多重分形基础上, 比较了两种海杂波的高尺度多重分形特性. 结果表明, 当尺度q > 10时, 纯海杂波的多重分形参数H(q) < 0, 而存在小目标的H(q) > 0, 此差异性为高尺度分形参数的海杂波背景小目标检测提供了判定依据. 所研究的两种方法均能实现不同海情下的小目标检测.

Small target detection in the background of sea clutter using fractal method

Because the detecting of the small target in the background of sea clutter is strongly dependent on sea condition, in this article we use fractional Brownian motion to model IPIX sea clutter and combine multifractal detrended fluctuation analysis (MF-DFA) to determine the fractal parameters for analyzing fractal and multifractal property of IPIX sea clutter. Based on the fact that Hurst parameter and fractal dimension can reflect the fractal property of data, a new parameter named fractal differential which has difference when the sea clutter with or without target is defined, thereby solving the problem of small target in sea clutter background. By comparing the multifractal parameters of two sea clutter, the experimental results show that H(q) is a special value which is bigger than zero when the sea clutter has a small target but smaller than zero when the sea clutter has no target if q is bigger than ten. Another method is proposed by using the difference of H(q). Two methods in this article can solve the problem of strong dependence of detecting the small target in different sea conditions on sea condition.