Multi-resolution error analysis of predicted absorption coefficients. Method and application to the infrared spectrum of methane at high temperature

A general method for the estimation of the confidence interval of molecular absorption coefficients is presented. Statistical numerical experiments are implemented to quantify the propagation of errors from line parameters to absorption coefficients as a function of the resolution. The method uses line parameter predictions (position and intensity) with estimated uncertainties derived from global polyad models. This work is especially intended to provide expert information for applications requiring theoretical predictions for which the present state of the art of line by line high-resolution modeling is not accurate enough to meet the desired precision. As an illustration, it is applied to predict the absorption coefficient of methane at high temperature involving simultaneously well known lower energy levels (cold bands) and higher energy levels with much lower precisions (hot bands). Potential extensions are discussed in the context of atmospheric remote sensing of astrophysical objects.