含卷浪Pierson-Moscowitz谱海面电磁散射研究

海尖峰的存在会导致雷达虚警概率的上升和多目标环境中检测性能下降,因此研究海尖峰现象意义重大.海尖峰现象的一个重要特点是海面的水平极化散射强度接近甚至大于垂直极化散射强度,卷浪被认为是产生海尖峰的一个原因.首先建立了卷浪和Pierson-Moscowitz谱海面的共同模型,利用矩量法研究了卷浪模型的水平和垂直后向电磁散射特征,包括入射频率、入射角、风速和风向对电磁散射特征的影响.发现在小擦地角情况和较大风速下超级现象(水平散射强度大于垂直极化散射强度)比较明显,从而推论出在小擦地角入射下产生海尖峰现象的概率较大.同时对时变卷浪在小擦地角入射时的海杂波幅值分布特性和多普勒谱进行了分析.

Modeling and electromagnetic scattering from the overturning wave crest

The presence of sea spikes can cause the radar false alarm probability rise and performance degradation of multi-target environment detection. Therefore, study of the phenomenon of sea spikes is of great significance. HH polarization scattering intensity close to or even greater than the VV polarization scattering intensity is an important feature of sea spike phenomenon. Overturning wave crest is considered to be one of the reasons of generating sea spike. In this paper, overturning wave crest model is introduced with the consideration of the wind speed, and the method of moment is used for studying HH and VV backward scattering coefficient for different incident frequencies, incident angles, wind speeds, and wind directions. It is found that super phenomenon (HH scattering intensity is greater than VV polarization scattering intensity) is more obvious in the cases of low grazing >and large wind speed, thus it is deduced that the sea spike phenomenon occurs with a high probability in the case of low grazing angle. Moreover, the distributions of sea clutter amplitude and Doppler spectra are also examined for the overturning wave crest model with low grazing >incidence.
Keywords： sea spike overturning wave crest electromagnetic scattering low grazing angle