微波传输中沙尘衰减的计算与仿真

Calculation and simulation of sand and dust attenuation in microwave propagation

沙尘衰减对高功率微波在大气中的传播有较大的影响,通过结合干沙的复介电常数公式与Ray提出的水的介电常数公式给出了沙尘衰减的计算模型,利用该模型分析了爆炸沙尘、车扬沙尘和自然沙尘的衰减.根据数值计算结果,仿真了不同含水量的沙尘衰减率随微波频率的变化,结果表明:在频率不是太高时,自然风沙和车扬沙尘对微波传输的影响不大,而爆炸环境下的沙尘衰减必须要考虑;沙尘衰减随水含量的增加而明显上升,此效应在较小差别的20%～30%水含量中处于饱和状态,这说明在高湿度热带地区的沙尘衰减将比沙漠和半沙漠地区的衰减大得多.

The sand and dust attenuation has a great effect on the microwave propagation in the air. The calculation model of the sand and dust attenuation was got, combining the formula of the complex dielectric constant of dry sand with the dielectric constant of water. The model analysed the attenuation of sand and dust produced by explosion, vehicle and nature, and simulated attenuation rate of sand with different content of water. The result of numerical calculation shows that natural sand and vehicular sand have little effect on microwave when the frequency is not very high, but the attenuation of explosive sand could not be ignored. It also shows the attenuation of explosive sand rises quickly along with the increase of water content. This effect reaches saturated state when the humidity ranges from 20% to 30%. Therefore, the sand and dust attenuation of high moisture tropical area is greater than that of desert or half-desert.