Detection of low observable moving target in sea clutter via fractal characteristics in fractional fourier transform domain
Detection of low observable moving target in sea clutter via fractal characteristics in fractional fourier transform domain
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DOI：
10.1049/iet-rsn.2012.0116
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发表时间：
2013-08
影响因子：
1.7
通讯作者：
Xiaolong Chen;J. Guan;You He;Jian Zhang
中科院分区：
文献类型：
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作者：
Xiaolong Chen;J. Guan;You He;Jian Zhang
对海上低可观测运动目标的有效检测在遥感和雷达信号处理中具有重要意义。海杂波的非高斯特性和缺乏精确的海杂波模型，使得基于统计的检测器很难进行检测。时域分形技术在强海杂波环境下也不能获得较高的检测概率。针对这一问题，利用分数阶傅里叶变换（FRFT）幅值的波动性，分析了IPIX数据集在FRFT域的分形特征，并提出了基于FRFT域分形特征的运动目标检测算法。首先，利用分数布朗运动模型建立FRFT域的分形模型，并采用两种判断和提取方法计算FRFT域的分形特征。研究发现，不同极化的海杂波在其对应的尺度不变区间内，在分数阶傅里叶变换域表现出分形特性，即自相似性。然后，我们发现，在最好的FRFT域的四个特定的分形统计可以提供有价值的信息，开发简单而有效的检测器。最后，将传统的幅度检测器与时域Hurst指数检测器进行了比较，结果证明了该检测器不需要复杂的运算，对低可观测运动目标具有上级检测能力。
Effective detection of low observable moving target at sea is important for remote sensing and radar signal processing. The non-Gaussian property of sea clutter and lack of accurate model make the detection difficult for statistics based detectors. Also the fractal techniques in time domain cannot achieve high detection probability in heavy sea clutter. To help solve the problems, fractal characteristics of IPIX datasets in fractional Fourier transform (FRFT) domain are analysed making use of the fluctuation of FRFT amplitudes and moving target detection algorithms are proposed based on the fractal characteristics in FRFT domain. Firstly, fractal model in FRFT domain is established with fractional Brownian motion model and two judgment and extraction methods are employed for calculating the fractal characteristics in FRFT domain. It is found that sea clutter of different polarisations exhibit fractal behaviours in FRFT domain, that is, self-similarity property, within its corresponding scale-invariant interval. Then, we find that four specific fractal statistics in the best FRFT domain can provide valuable information for developing simple and effective detectors. Finally, traditional amplitude detector and Hurst exponent detector in time domain are compared and the results prove the superior detection ability of low observable moving target without complex computations.