A fast FRFT based detection algorithm of multiple moving targets in sea clutter
A fast FRFT based detection algorithm of multiple moving targets in sea clutter
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DOI：
10.1109/radar.2010.5494587
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发表时间：
2010-05
期刊：
影响因子：
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通讯作者：
Xiaolong Chen;J. Guan
中科院分区：
文献类型：
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作者：
Xiaolong Chen;J. Guan
在多运动目标检测与估计模型的基础上，提出了一种基于小波包变换（WPT）和分数阶傅里叶变换（FRFT）的海杂波中弱运动目标检测算法。该方法将小波包变换的多分辨率特性和线性调频信号在分数阶傅里叶变换域能量集中性好的特点结合起来。该方法首先利用最小香农熵计算最优小波树，然后采用阈值删失方法对不同频段的海杂波进行抑制。然后，以分数阶傅里叶变换后信号的绝对幅度作为检验统计量，利用阈值在二维空间搜索峰值。参数估计采用分级迭代法，计算速度快，多目标间的阴影问题采用CLEAN方法解决。最后，利用IPIX数据进行仿真，结果表明该算法对海杂波中的低可观测运动目标具有良好的检测性能。
On the basis of the detection and estimation model of multiple moving targets, a new algorithm based on wavelet packet transform (WPT) and fractional Fourier transform (FRFT) is proposed for weak moving targets detection in sea clutter. The multi-resolution property of WPT and the characteristic of good energy concentration on LFM signals in FRFT domain are combined together. At first, optimal wavelet tree is calculated using “minimum Shannon entropy” and threshold censored method is used to suppress sea clutter of different frequency bands. Then, take the absolute amplitude of signals after FRFT as test statistic and search for peaks in two dimensions with the threshold. Grading iterative method is used for parameter estimation with fast calculation speed and the shading problem between multiple targets is solved through “CLEAN” method. In the end, simulations with IPIX data indicate that the proposed algorithm has good performance of detecting low-observable moving targets in sea clutter.