In this paper we present the results of Н<sub>2</sub> <sup>16</sup>О absorption spectrum investigation recorded by a high resolution Fouriertransform spectrometer IFS-125M in the region 15500 – 16000 cm<sup>-1</sup>. Absorption path of 34.8 m and resolution of 0.03 см<sup>-1</sup> were chosen to record the spectrum. White type multipass absorption cell with a basic length of 60 cm were used. Light-emitting diode (LED) was applied as a source of radiation. Signal-to-noise ratio is about 10<sup>4</sup>, making it possible to measure parameters of lines with intensity up to 2*10<sup>-27</sup> cm/molecule. Least-square-fitting algorithm was used to retrieve of the spectroscopic parameters from measured spectral data set. Spectral line positions and line intensities derived from the fitting were compared to data obtained in previous works.
Measurements of water vapor absorption spectra in the visible spectral region near 0.44 mkm are performed using FTspectrometer IFS-125M and Light-emitting diode (LED) as source of radiation. Water vapor spectrum has been obtained by averaging over 17136 scans recorded at 34,8 m optical path length, temperature 24 ± 1 С and pressure of sample 24,8 mBar. Due to strong emission of LED source it was possible to achieve signal-to-noise ratio about 104 and to record weak lines with intensities of 6 10-27 cm/molecule. Comparisons with results of early works are made.
The results of study of the atmospheric oxygen complexes (O<sub>2</sub>)<sub>2</sub> by means ground based spectroscopic technique in
Tomsk region, Western Siberia, are presented The absorption of the oxygen complexes (O<sub>2</sub>)<sub>2</sub> has been investigated in the
visible and near-infrared spectral region under clear-sky conditions using a high resolution Fourier transform
spectrometer (FTS) IFS-125 M. The total contents of the atmospheric (O<sub>2</sub>)<sub>2</sub> and O<sub>3</sub> absorber were derived from the fit to
experimental data. The seasonal variability of atmospheric oxygen complexes and in addition ozone amounts was
detected. The estimates performed show the dependence of oxygen complexes total contents from temperature.