沙尘暴中球形沙粒局部带电对电磁波的交叉去极化效应

Cross Depolarization Effect of Electromagnetic Wave by Partially Charged Spherical Sands in Sandstorms

基于小粒子散射的Rayleigh近似,给出局部带电小圆球粒子在不同极化方式入射波作用下的前向散射振幅函数,以及差分衰减、差分相移表达式,同时计算了线极化毫米波在带电沙尘暴中传播的交叉去极化分辨率。结果表明,圆球粒子局部带电时也会使得入射极化波产生去极化效应,且入射波的去极化效应随着电荷分布角的增加先增强后减弱,在90°角达到最大值;随着荷质比、入射波频率的增加不断增强,随着能见度的增加不断减小。结果说明,在沙尘暴中的无线电接收装置设计时必须考虑到沙粒带电对通信信号的去极化影响。

Based on the Rayleigh approximation, the electromagnetic wave illumining on a partially charged sand particle, the forward scattering amplitude function, and the expression of differential attenuation and differential phase shift are derived. We calculated the cross depolarization discrimination of linear polarized wave propagated on the charged dust storm. The results indicate that the partially charged spherical particle also can make the incident wave depolarized, and the depolarization effect firstly increases and then decreases with the charged angle increasing. When the charged angle is equal to 90, the cross depolarization effect reaches up to its maximum. With the increasing of the charge-mass ratio and the frequency of the electromagnetic wave, the cross depolarization effect increases, but which decreases with the visibility increasing. All these results show that it is important to take into account the depolarization effect of charged sands on the radio receiver＇s design.