低太赫兹频段ITU大气吸收模型伪线谱的修正研究

针对ITU建议书ITU-R P.676大气吸收模型在太赫兹频段误差偏大的问题，基于分子响应理论的大气模型（atmosphere model，AM）提出了一条低误差的、符合ITU模型规范的新伪线谱(new pseudo-line, nPL). 通过多目标粒子群算法对多参数进行拟合，设定多个目标函数，在尽可能不增大300 GHz以下大气吸收衰减计算误差的同时，减小了300 GHz以上太赫兹频段的误差. 结果表明:在标准大气压下使用nPL，使得ITU模型在900 GHz以内的大气吸收衰减计算误差得到了有效降低；在5～20 °C、0.6～1.0 atm条件下表现也较为良好. 本文所提的nPL模型提供了更精确的大气吸收衰减值，对未来太赫兹波的传输建模、仿真分析及系统设计均有指导意义.

Correction of pseudo-line of ITU atmospheric absorption model in low terahertz band

Aiming at the large offset error of ITU Recommendation ITU-R P.676 atmospheric absorption model in terahertz, a new pseudo-line (nPL) is proposed to improve the ITU model based on the atmosphere model (AM) of the molecular response theory. The particle swarm algorithm is used to set multiple objective functions to fit multiple parameters. The nPL reduces the atmospheric absorption and attenuation error of the terahertz spectrum above 300 GHz without increasing the calculation error below 300 GHz. Results show that using nPL the calculation error of the atmospheric attenuation has been effectively reduced compared with that in the ITU within 900 GHz under standard atmospheric pressure. In addition, the model performs well underthe conditions of 5?20 °C and 0.6?1.0 atm. The nPL provides more accurate atmospheric absorption and attenuation values, which is significant for propagation modeling, simulation, and system design of terahertz propagation waves.