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

Abstract

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.