基于HITRAN数据库,对比了大气主要成份分子对THz波段的吸收.从Mie理论出发,结合雾滴粒子谱分布,分析了不同波长信号雾滴粒子群的平均体系散射特性.采用蒙特卡罗方法,得到了红外波段和THz波段雾天气的透过率、反射率,以及前向、后向散射强度.结果表明:THz波段内,频率越低,透过率越高,反射率越低,后向散射强度越小;相同传输距离下,THz波段比红外波段具有更好的透射能力;相同散射角下,红外波段信号前向散射强度大于THz波段.该研究结果对THz技术在大气空间中的应用具有重要意义.
Based on the High-resolution Transmission(HITRAN)molecular spectroscopic database,the absorptions of the THz wave by the main atmospheric molecules were contrasted.According to the Mie theory and with the fog particle size distribution considered,the average scattering characteristics of fog droplet particles were analyzed with different incident wavelengths.The transmissivity and the reflectivity and the forward and backward scattering intensities of the THz signal in fog,as well as the infrared light,were investigated with Monte Carlo method.The result shows that in THz region,the lower the frequency,the higher the transmissivity,the lower the reflectivity,the weaker the backward scattering intensity;additionally,with a same distance the THz wave has a better transmission capacity than the infrared light;meanwhile,the forward scattering intensity of the infrared light is stronger than the THz wave with a same scattering angle.The research in the paper is of great significance to the application of the terahertz technology on the atmospheric space.