LINE STRENGTHS OF METHANE IN THE $7 \mu m$ and $2.5 \mu m$ REGIONS

Abstract

Line positions and strengths of methane from $1200 to 1700 cm^{-1}$ and $4136 to 4666 cm^{-1}$ have been determined from spectra recorded at $0.0054 to 0.0106 cm^{-1}$ resolution using a Fourier transform spectrometer at Kitt Peak National Observatory. Measurements are done by a least squares procedure that iterates the values of position, strength and continuum parameters in order to minimize the difference between the observed spectrum and a synthetic spectrum calculated at appropriate instrumental and gas sample conditions. Line strengths are determined with accuracies of 2% or better for single unblended lines of two bands in the $7\mu m$ region $(\upsilon_{4} and \upsilon_{2})$ and three bands in the $2.5 \mu m$ region $(\upsilon_{1} + \upsilon_{4}, \upsilon_{3} + \upsilon_{4} and \upsilon_{2} + \upsilon_{3})$.