高空飞行器尾焰亚毫米波临边探测模拟与分析

由于许多气体,特别是卤族元素在亚毫米波段有特殊吸收谱线,因此亚毫米波临边探测具有重要意义。文章基于ARTS正向模型,模拟并分析了飞行器主要尾焰成分在亚毫米波段临边探测敏感性。基于模拟的高空飞行器尾焰流场比较了不同大气背景对尾焰临边探测的影响;并模拟了亚毫米波临边与天底两种模式对尾焰流场的探测。研究结果表明在中高空处,临边探测对尾焰成分H2O、O2、OH及HCl的浓度变化很敏感,5倍浓度的变化使某些频率处的亮温分别提高约80 K、80 K、5 K与50 K。研究结果也表明,亚毫米波临边探测可以探测到尾焰流场,而天底探测则无法探测出尾焰流场。

Sub-millimeter wave limb sounding simulation of the plume flow of a high-flying vehicle

The development of a sub-millimeter (0.1 mm to 1.0 mm or 300 GHz to 3 THz) limb sounding technique has enhanced our knowledge of O₃ processes. Sub-millimeter wave limb sounding is important because the sub-millimeter includes many spectral lines of trace gases, particularly the halogen family. This study aims to investigate the possibility of limb sounding of a high-flying vehicle plume. ARTS forward model is used to simulate the limb sounding of the plume compositions to study their sensitivity. The sub-millimeter wave limb sounding is sensitive to the concentration variations in H₂O, O₂, OH, and HCl. When their concentration is increased five times, their limb sounding bright temperature will increase by 80 K, 80 K, 5 K, and 50 K, respectively. However, sub-millimeter wave limb sounding is not sensitive to concentration variations in CO, CO₂, and NO. Based on a simulated trail of a vehicle flying at an altitude of 15 km, the sub-millimeter wave limb sounding radiance temperatures of the plume under different atmospheric backgrounds are calculated and compared; the different radiance temperatures of limb sounding and nadir viewing are also compared. The plume of the flying vehicle can be detected with a sub-millimeter wave limb sensor under any atmospheric background. However, it cannot be detected with the nadir viewing sensor. Therefore, the sub-millimeter wave limb sounding technique has an advantage over nadir viewing in detecting the plume of a high-flying vehicle, and its atmospheric background affects the limb sounding of the plume.