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本文主要研究海杂波频谱的多重分形特性并分析其影响因素.首先介绍了将多重分形理论引入到海杂波频谱分析中的理论基础,然后,采用X波段与S波段相参雷达实测数据验证海杂波频谱的多重分形特性,并采用多重分形去趋势起伏分析(MF-DFA)法对海杂波频谱进行多重分形特性分析,分析结果表明海杂波频谱是一种受长程相关性和概率分布共同影响的多重分形序列,并且频域多重分形参数—广义Hurst指数对海杂波单元与目标单元具有一定的区分能力.此外,通过分析广义Hurst指数的影响因素还发现FFT时所采用的时间序列长度对广义Hurst指数影响相对较大,而FFT点数对其影响相对较小.
This paper mainly studies the multifractal characteristics of the sea clutter spectrum and analyzes its influencing factors.Firstly, the theoretical basis for introducing the multifractal theory into the sea clutter spectrum analysis is introduced. Then, the measured data of the X-band and S-band coherent radar are validated The multifractal characteristics of the sea clutter spectrum are analyzed. The multifractal characteristics of the sea clutter spectrum are analyzed by the MF-DFA method. The results show that the sea clutter spectrum is a multi-fractal model subject to long-range correlation and probability Distribution and multifractal sequences, and the multifractal parameter in frequency domain - generalized Hurst exponent has a certain ability of distinguishing sea clutter unit from target unit. In addition, by analyzing the influencing factors of generalized Hurst exponent, we find that the time used in FFT The length of the sequence has a relatively large effect on the generalized Hurst index, while the impact of the FFT points on it is relatively small.