摘要
针对传统分形方法在海杂波研究中的局限性,为了有效检测海面弱小目标,本文提出一种分形理论与时频分析相结合的海面弱目标检测算法。首先通过分数阶Fourier变换(FRFT)将时域回波信号变换到时频联合域,在FRFT的最佳变换域,信号的能量得以聚集、信杂比得以提高。然后提取改进的空间分形特征差异作为检测统计量,将其作为目标检测的依据。利用IPIX雷达实测数据进行验证,实验表明本文的算法可以有效避免门限效应的影响,克服了传统方法中使用固定分数维门限检测效果不佳的缺陷,提高了海事雷达的弱目标检测性能。
In consideration of limitations of traditional factal methods in sea clutter study, aiming at de-tecting weak targets on sea surface effectively, we proposed an detection algorithm combining fractal theo- ry and time-frequency analysis. Firstly, it transformed the radar echo from time domain to time-frequency domain through the fractional Fourier transform (FRFT) to improve the signal-to-clutter ratio. Then it extracted the modified spatial fractal character differences as the test statistics. IPIX real-life sea clutter was used for verification, and the results showed that the proposed algorithm can effectively avoid the in- fluence of threshold effect. The proposed algorithm overcomed the defects resulting from taking fixed fractal dimension threshold to detect targets in traditional method, and effectively improved the weak tar-get detection capability of maritime radar.
出处
《中国海洋大学学报(自然科学版)》
CAS
CSCD
北大核心
2013年第3期92-97,共6页
Periodical of Ocean University of China
基金
国防基础科研计划项目(B1120110005)资助