Line mixing in the 60-GHz atmospheric oxygen band: Comparison of the MPM and ECS model

Precise profiles of the 60-GHz molecular oxygen band recorded earlier in a wide temperature range by means of a resonator spectrometer at atmospheric pressure were treated. High signal-to-noise ratio allows careful study of the band shape taking into consideration the mixing effect. Comparative analysis of the band profile calculated by an extended MPM (Millimeter-wave Propagation Model) and by the ECS (Energy Corrected Sudden) approximation model is presented. Some limitations of the MPM approach are discussed on the basis of the comparison of the two models. Interbranch coupling is shown to make a noticeable contribution to absorption which means that it should be taken into account as it is expected to improve band profile modeling accuracy.

► Two approaches to 60-GHz molecular oxygen band profile modeling are compared. ► ECS approach based band profile model is submitted. ► Improvement of 60-GHz molecular oxygen band profile modeling is demonstrated. ► ECS approach is more precise and physically reasonable at low temperatures.