A multispectrum fitting procedure to deduce molecular line parameters:: Application to the 3-0 band of 12C16O

To deduce accurate infrared molecular line parameters (positions at zero pressure, pressure-shifting and pressure-broadening coefficients, collisional narrowing coefficients, and intensities) from rovibrational spectra, an automatic method based upon a multispectrum fitting procedure has been set up, able to treat simultaneously several laboratory Fourier transform spectra. A validation of this method, using absorption spectra of the 3-0 vibrational band of CO around 6 350 cm(-1), already used to measure line intensities and self-broadening coefficients, is presented, and the advantages of the method are pointed out. The self collisional narrowing of CO was observed and determined for the first time in Fourier transform spectra: beta (o) = 0.028 +/- 0.004 cm(-1) atm(-1) at about 296 K.