南京大学学报（自然科学版）2017，Vol.53Issue(4)：731-737,7.DOI:10.13232/j.cnki.jnju.2017.04.016
FRFT域内的海杂波多重分形特性与目标检测
Multifractal property and target detection of sea clutter in FRFT domain
摘要
Abstract
How to detect small targets from sea clutter is a hot issue in radar signal processing.The sea clutter has multiple fractal characteristics and the small target detection is carried out by using different fractal characteristics between sea clutter and the target echo.The complexity of the sea clutter determines that the fractal dimension is generally larger and fractal dimension of target is smaller due to the smoothness of the surface.When detecting small targets,the sea clutter is strong and need to be suppressed.Fractional Fourier Transform(FRFT)is a good way to improve the signal to clutter ratio(SCR).After the FRFT of the moving target,the peak can be formed in the best transform domain.But the sea clutter is difficult to accumulate the effective peak.Combined with these characteristics,this paper proposes a method of combining multifractal features in FRFT domain.On the basis of multifractal characteristic,this paper compares the fractal dimension of time domain and FRFT domain,which proves that FRFT can effectively gather the energy of target unit and increases the difference between pure sea clutter and target unit.The multifractal dimension and intercept in FRFT domain are combined as a two-dimensional decision space for detecting small targets.Simulation with data of Ice Multiparameter Imaging X-Band Radar,the results proves that there is a significant difference between the sea clutter and the small target in the decision space.Meanwhile,it is verified that the method proposed in this paper can effectively improve the ability of small target detection in sea clutter.关键词
小目标/分数阶傅里叶变换/分形维轨迹/截距Key words
small target/FRFT/fractal dimension trajectory/intercept分类
信息技术与安全科学引用本文复制引用
顾智敏,张兴敢,王琼..FRFT域内的海杂波多重分形特性与目标检测[J].南京大学学报（自然科学版）,2017,53(4):731-737,7.基金项目
江苏省基础研究计划(BK20151391) （BK20151391）
