实测海杂波数据的多普勒谱特性

Doppler Spectra Property of Measured Sea Clutter Data

针对海杂波背景下目标检测问题的实际需要,采用两种不同波段、不同极化的实测数据,对海杂波的多普勒谱特性进行了分析和建模。首先对海表面的散射模型和多普勒谱的产生机理进行了简要的介绍。其次,从时间相关性分析的角度入手,揭示了多普勒谱的特点。然后,通过非参数化的Welch方法进行谱估计,重点分析了极化对多普勒谱的谱宽、偏移、对称性、动态范围以及拖尾的影响,并进行了机理解释。最后,分别采用高斯模型、AR模型和谐波模型对多普勒谱进行建模和拟合。结果表明,谐波模型能得到最优的拟合效果。文中的研究结论可以为目标检测算法提供先验信息和理论依据,在实际应用中具有重要的借鉴价值。

According to the actual requirement of target detection problems under sea clutter environ- ment, this paper focuses on the analysis and modeling of sea clutter Doppler spectra with two kinds of meas- ured clutter data with different bands and polarizations. Firstly, a brief introduction is given to the scauering model and the mechanism of Doppler spectra. Then, the property of Doppler spectra is revealed from the analysis of time correlation. Through the nonparametrie Welch spectral estimation method, the influences of polarization on spectral width, displacement, symmetry, dynamic range and tail are analyzed, and emphasis and mechanism explanation are also given. At last, the Gaussian model, AR model and harmonic model are used to model and fit the Doppler spectra. Final results show that harmonic model can achieve the best fit effect. The research result of this paper can offer prior information and theoretical foundation for target de- tection algorithm, and has important reference values in actual applications.