Transmittance Calculation of Terahertz Wave in Fog Based on MC Method

The basic physical characteristics of fog are analysed in this paper. According to Mie theory, the average extinction parameters of THz wave and infrared radiation of fog droplets at different frequencies are calculated. Based on the weighted MC method, the relationship between the transmittance of THz wave in advection fog and radiation fog, visibility and transmission distance is calculated and compared with the transmittance of infrared radiation. The results show that under the same conditions, the lower the frequency of THz wave is, the higher the transmittance is, and the transmittance of terahertz wave is much larger than that of infrared radiation. It has stronger ability to penetrate thick fog. When the visibility is the same, advection fog has larger droplets than radiation fog. The transmission of terahertz wave in radiation fog is obviously larger than that in advection fog. Advection fog has greater influence on the transmission of terahertz wave.