Methane line shapes and spectral line parameters in the 5647 - 6164 cm−1 region

Approximately seventy isolated and overlapping methane absorption lines in the 5647 − 6164 cm−1 spectral region were processed with seven line profiles accounting for all main line shape forming physical mechanisms in different combinations. It was shown that at low methane pressures the conventional Nelkin-Ghatak line profile gives satisfactory results in retrieving line parameters as opposed to the Voigt profile. It was found that most of the considered lines do not interfere. The FTS instrumental function elimination technique based on Doppler-broadened line's records was applied, and its applicability was proved.