Influence of Uncertainty of Probabilities of Spontaneous Emission on the Temperature Behavior of the Collisional Self-Broadening Coefficients of Spectral Lines of CO2 Molecules

Abstract

The influence of deviation of the values of spontaneous emission probability A on the temperature behavior of collisional self-broadening coefficients γ(T) of spectral lines of CO2 molecules has been analyzed for solution of the inverse problem of simultaneous determination of A and γ from an array of absorption coefficients. Investigations have been carried out for two cases: (i) the calculations are performed using A = 0.2022 s–1 (HITRAN2012); (ii) the A values are obtained via minimization of the sum of weighted squared deviations of the absorption coefficients. It is established for the two calculation versions that, when measuring the absorption coefficients with an error of no more than 0.05αmin, the deviation of the functions γ(T) does not exceed 5% in the temperature range of 300–700 K. No causal relationship is observed between parameters γ and A. The least-squares method makes it possible to correctly calculate the temperature dependences of the collisional self-broadening coefficients of CO2 lines at simultaneous determination of parameters γ(T) and A.